<SEC-DOCUMENT>0000950123-11-046575.txt : 20110506
<SEC-HEADER>0000950123-11-046575.hdr.sgml : 20110506
<ACCEPTANCE-DATETIME>20110506154902
ACCESSION NUMBER:		0000950123-11-046575
CONFORMED SUBMISSION TYPE:	SC 13D
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20110506
DATE AS OF CHANGE:		20110506

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LoopNet, Inc.
		CENTRAL INDEX KEY:			0001353209
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE AGENTS & MANAGERS (FOR OTHERS) [6531]
		IRS NUMBER:				770463987
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-82495
		FILM NUMBER:		11819310

	BUSINESS ADDRESS:	
		STREET 1:		185 BERRY STREET
		STREET 2:		SUITE 4000
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94107
		BUSINESS PHONE:		(415) 243-4200

	MAIL ADDRESS:	
		STREET 1:		185 BERRY STREET
		STREET 2:		SUITE 4000
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94107

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COSTAR GROUP INC
		CENTRAL INDEX KEY:			0001057352
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		IRS NUMBER:				522091509
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D

	BUSINESS ADDRESS:	
		STREET 1:		1331 L STREET NW
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20005
		BUSINESS PHONE:		2023466500

	MAIL ADDRESS:	
		STREET 1:		1331 L STREET NW
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20005
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D
<SEQUENCE>1
<FILENAME>w82694sc13d.htm
<DESCRIPTION>SC 13D
<TEXT>
<HTML>
<HEAD>
<TITLE>sc13d</TITLE>
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<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 1pt solid black; font-size: 1pt">&nbsp;</DIV>




<DIV align="center" style="font-size: 14pt; margin-top: 12pt"><B>UNITED STATES<BR>
SECURITIES AND EXCHANGE COMMISSION</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B>Washington, D.C. 20549</B>
</DIV>

<DIV align="center" style="font-size: 18pt; margin-top: 12pt"><B>SCHEDULE 13D</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B>Under the Securities Exchange Act of 1934</B></DIV>


<DIV align="center" style="font-size: 12pt"><B>(Amendment No. </B><U>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><B>)*</B></DIV>


<DIV align="center" style="font-size: 24pt; margin-top: 12pt"><B>LOOPNET, INC.</B>
</DIV>

<DIV align="center" style="font-size: 10pt"><DIV style="width: 100%; border-bottom: 1px solid #000000; FONT-size: 1px">&nbsp;</DIV></DIV>


<DIV align="center" style="font-size: 10pt">(Name of Issuer)</DIV>



<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>Common Stock, par value $0.001 per share</B>
</DIV>

<DIV align="center" style="font-size: 10pt"><DIV style="width: 100%; border-bottom: 1px solid #000000; FONT-size: 1px">&nbsp;</DIV></DIV>


<DIV align="center" style="font-size: 10pt">(Title of Class of Securities)</DIV>



<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>543524300</B>
</DIV>

<DIV align="center" style="font-size: 10pt"><DIV style="width: 100%; border-bottom: 1px solid #000000; FONT-size: 1px">&nbsp;</DIV></DIV>


<DIV align="center" style="font-size: 10pt">(CUSIP Number)</DIV>



<DIV align="Center" style="font-size: 10pt; margin-top: 12pt">CoStar Group, Inc.<BR>
1331 L Street, NW<BR>
Washington, DC 20005<BR>
Attention: General Counsel<BR>
(202)&nbsp;346-6500
</DIV>

<DIV align="center" style="font-size: 0pt; margin-top: 0pt"><DIV style="width: 100%; border-bottom: 1px solid #000000; FONT-size: 1px">&nbsp;</DIV>
</DIV>

<DIV align="center" style="font-size: 10pt">(Name, Address and Telephone Number of Person Authorized to</DIV>


<DIV align="center" style="font-size: 10pt">Receive Notices and Communications)</DIV>



<DIV align="center" style="font-size: 10pt; margin-top: 18pt">April&nbsp;27, 2011
</DIV>

<DIV align="center" style="font-size: 10pt"><DIV style="width: 100%; border-bottom: 1px solid #000000; FONT-size: 1px">&nbsp;</DIV></DIV>


<DIV align="center" style="font-size: 10pt">(Date of Event which Requires Filing of this Statement)</DIV>



<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

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    <TD width="1%" nowrap align="left">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>If the filing person has previously filed a statement on Schedule&nbsp;13G to report the
acquisition that is the subject of this Schedule&nbsp;13D, and is filing this schedule
because of &#167;&#167;240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. <FONT style="font-family: Wingdings">&#111;</FONT></TD>
</TR>

</TABLE>
</DIV>

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<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>





<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

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    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
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<TR valign="bottom">
    <TD align="left" valign="top">Schedule&nbsp;13D
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">Page 2 of 8</TD>
</TR>
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<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
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<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
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<TD width="9%">&nbsp;</TD>
</TR>
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<TR valign="bottom">
<TD valign="top" nowrap><DIV style="margin-left:0px; text-indent:-0px">CUSIP No.</DIV></TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid #000000">543524300&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top"></TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 0px solid #000000">&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 0px solid #000000">&nbsp;</DIV></TD>
</TR>
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</TABLE>
</DIV>

<P>&nbsp;<DIV style="width: 100%; border: 1px solid black"><DIV align="center">

<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="1" width="100%">
<!-- Begin Table Head --><TR style="font-size: 1px">
<TD width="5%">&nbsp;</TD>
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="83%">&nbsp;</TD>
</TR>

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<TR valign="bottom">
<TD valign="middle" align="center"><FONT style="font-size: 18pt"><B>1</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">NAME OF REPORTING PERSON<BR>
<BR>
<BR>IRS IDENTIFICATION NO.<BR>CoStar Group, Inc.<BR>52-2091509</TD>
</TR>
<TR valign="bottom">
<TD>&nbsp;</TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>2</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP <BR><BR></TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(a)&nbsp;&nbsp;&nbsp;<FONT face="wingdings" size="2">&#111;</FONT>&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(b)&nbsp;&nbsp;&nbsp;<FONT face="wingdings" size="2">&#111;</FONT>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>3</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SEC USE ONLY</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>4</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SOURCE OF FUNDS </TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">Not Applicable (see Item 3)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>5</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>6</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CITIZENSHIP OR PLACE OF ORGANIZATION</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">Delaware
</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid #000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid #000000; border-right: 1px solid #000000"><FONT style="font-size: 18pt"><B>7</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE VOTING POWER</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">NUMBER OF</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid #000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">SHARES</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid #000000; border-right: 1px solid #000000"><FONT style="font-size: 18pt"><B>8</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED VOTING POWER</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">BENEFICIALLY</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">OWNED BY</TD>
<TD>&nbsp;</TD>
<TD>12,890,313*</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid #000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>


<TR valign="bottom">
<TD align="center" colspan="3">EACH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid #000000; border-right: 1px solid #000000"><FONT style="font-size: 18pt"><B>9</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE DISPOSITIVE POWER</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">REPORTING</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">PERSON</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>
<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid #000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">WITH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid #000000; border-right: 1px solid #000000"><FONT style="font-size: 18pt"><B>10</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED DISPOSITIVE POWER</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>11</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">12,890,313*</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>12</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF THE AGGREGATE AMOUNT IN ROW (11)&nbsp;EXCLUDES CERTAIN SHARES </TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT>
</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>13</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">32.3&#37;</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>14</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">TYPE OF REPORTING PERSON </TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CO</TD>
</TR>
<!-- End Table Body --></TABLE>
</DIV>
</DIV>

<DIV style="font-size: 10pt; margin-top: 3pt; margin-left: 5pt; text-indent:-5pt">*Beneficial ownership of 12,890,313 shares of the Issuer&#146;s Common
Stock (consisting of 5,449,837 shares of Common Stock and 50,000 shares of Series A Convertible Preferred Stock of the Issuer
convertible into 7,440,476 shares of Common Stock) referred to herein is being reported hereunder solely because the
Reporting Person may be deemed to have beneficial ownership of such shares as a result of the voting and support
agreement described in Item 4 hereof. Neither the filing of this Statement on Schedule 13D nor any of its
contents shall be deemed to constitute an admission by any reporting person that it is the beneficial owner of
any of the Issuer&#146;s Common Stock referred to herein for purposes of Section 13(d) of the Securities Exchange Act of 1934, as
amended, or for any other purpose, and such beneficial ownership is expressly disclaimed by each reporting person
</DIV>

<DIV style="font-size: 10pt; margin-top: 3pt">
</DIV>

<DIV style="font-size: 10pt; margin-top: 3pt">
</DIV>

<DIV style="font-size: 10pt; margin-top: 3pt">
</DIV>


<P align="center" style="font-size: 10pt">

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<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
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    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
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<TR valign="bottom">
    <TD align="left" valign="top">Schedule&nbsp;13D
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">Page 3 of 8</TD>
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<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;1. Security and Issuer</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This statement on Schedule&nbsp;13D (&#147;Schedule&nbsp;13D&#148;) relates to the shares of common stock, par
value $0.001 per share (the &#147;Common Stock&#148;) of LoopNet, Inc., a Delaware corporation (the
&#147;Issuer&#148;). The address of the principal executive office of the Issuer is 185 Berry Street, Suite
4000, San Francisco, CA 94107.
</DIV>
<!-- link2 "Item 2. Identity and Background" -->
<DIV align="left"><A NAME="W82694001"></A></DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;2. Identity and Background</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This statement is being filed by CoStar Group, Inc., a Delaware corporation (the &#147;Reporting
Person&#148;). The address of the principal office of the Reporting Person is 1331 L Street, NW,
Washington, DC 20005. Information as to each of the executive officers and directors of the
Reporting Person is set forth on Schedule&nbsp;I hereto.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Reporting Person is the number one provider of information and analytic services to the
commercial real estate industry in the United States (U.S) and United Kingdom U.K.) based on the
fact that the Reporting Person offers the most comprehensive commercial real estate database
available, has the largest research department in the industry, provides more information and
analytic services than any of its competitors and believes that it generates more revenues than any
of its competitors.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;During the last five years, neither the Reporting Person nor, to the best knowledge of the
Reporting Person, any of the other persons identified in Schedule&nbsp;I: (i)&nbsp;has been convicted in a
criminal proceeding (excluding traffic violations or similar misdemeanors); or (ii)&nbsp;was a party to
a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result
of such proceeding was or is subject to a judgment, decree or final order enjoining future
violations of, or prohibiting or mandating activities subject to, federal or state securities laws
or finding any violation with respect to such laws.
</DIV>
<!-- link2 "Item 3. Source and Amount of Funds or Other Consideration" -->
<DIV align="left"><A NAME="W82694002"></A></DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;3. Source and Amount of Funds or Other Consideration</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As more fully described in Item&nbsp;4 hereof, the holders of the Issuer&#146;s Series&nbsp;A Convertible
Preferred Stock, par value $0.001 per share (the &#147;Series&nbsp;A Convertible Preferred Stock&#148;), along
with certain executive officers of the Issuer and the members of the Issuer&#146;s board of directors
(collectively, the &#147;Stockholders&#148;), who are the record and beneficial owners of an aggregate of
5,449,837 shares of Common Stock and 50,000 shares of Series&nbsp;A Convertible Preferred Stock (which
50,000 shares are convertible into 7,440,476 shares of Common Stock) (all such shares,
collectively, the &#147;Subject Shares&#148;), entered into a Voting Agreement (as defined in Item&nbsp;4) with
the Reporting Person and the Issuer. The Subject Shares have not been purchased by the Reporting
Person, and thus no funds were used for such purpose. The Reporting Person did not pay additional
consideration to the Stockholders in connection with the execution and delivery of the Voting
Agreement. A list of the Stockholders party to the Voting Agreement is set forth on Schedule&nbsp;II
hereto.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Stockholders entered into the Voting Agreement to induce the Reporting Person to enter
into the Merger Agreement described in Item&nbsp;4.
</DIV>

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<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;4. Purpose of Transaction</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Merger Agreement</I></B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On April&nbsp;27, 2011, the Reporting Person, the Issuer and Lonestar Acquisition Sub, Inc., a
Delaware corporation and a wholly-owned subsidiary of the Reporting Person (&#147;Merger Sub&#148;) entered
into an Agreement and Plan of Merger (the &#147;Merger Agreement&#148;). Pursuant to the Merger Agreement,
and subject to the terms and conditions set forth therein, Merger Sub will be merged with and into
the Issuer (the &#147;Merger&#148;), with the Issuer continuing as the surviving corporation in the Merger
and a wholly-owned subsidiary of the Reporting Person.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As a result of the Merger, each outstanding share of Common Stock, other than shares owned by
the Reporting Person, Merger Sub or the Issuer (which will be cancelled and retired) and other than
those shares with respect to which appraisal rights are properly exercised and not withdrawn, will
be converted into a unit consisting of (i) $16.50 in cash, without interest and (ii)&nbsp;0.03702 shares
of the Reporting Person&#146;s common stock. Each outstanding share of the Issuer&#146;s Series&nbsp;A
Convertible Preferred Stock will be converted into the right to receive the foregoing consideration
on an as-converted basis.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Consummation of the Merger is subject to certain conditions, including, among others, (i)&nbsp;the
adoption of the Merger Agreement by the Issuer&#146;s stockholders, (ii)&nbsp;the absence of any law or order
prohibiting the closing, (iii)&nbsp;the expiration or termination of the applicable waiting period under
the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended and (iv)&nbsp;declaration of
effectiveness of the Registration Statement on Form S-4 to be filed by the Reporting Person.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B><I>Voting Agreement</I></B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As a condition and inducement to the Reporting Person entering into the Merger Agreement, the
Stockholders entered into a Voting and Support Agreement, dated as of April&nbsp;27, 2011, with the
Reporting Person and the Issuer (the &#147;Voting Agreement&#148;) with respect to (i)&nbsp;the Subject Shares,
and (ii)&nbsp;any other voting securities of the Issuer that the Stockholders acquire record and/or
beneficial ownership of after the date of the Voting Agreement, including by purchase, as a result
of a stock dividend, stock split, recapitalization, combination, reclassification, exchange or
change of such shares, or upon exercise, conversion or settlement of any securities, including
Common Stock issued upon conversion of the Series&nbsp;A Convertible Preferred Stock or upon exercise or
settlement of stock options and restricted stock units granted pursuant to any Issuer equity plan
(collectively, the &#147;Covered Shares&#148;).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Subject to the terms and conditions of the Voting Agreement, each Stockholder has agreed that,
during the term of the Voting Agreement, it shall at any meeting of the stockholders of the Issuer,
however called and in connection with any written consent of the stockholders of the Issuer (a)
appear at such meeting or otherwise cause such Stockholder&#146;s Covered Shares to be counted as
present thereat for the purpose of calculating a quorum, and (b)&nbsp;vote, or cause to be voted at such
meeting, all of such Stockholder&#146;s Covered Shares (I)&nbsp;in favor of the adoption of the Merger
Agreement and in favor of any related proposal in furtherance thereof, (II)&nbsp;against any action or
agreement that would reasonably be expected to result in a breach of any covenant,
</DIV>

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</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">representation or warranty or any other obligation or agreement of the Issuer contained in the
Merger Agreement or of such Stockholder contained in the Voting Agreement, and (III)&nbsp;against any
Acquisition Proposal (as defined below) and against any other action, agreement or transaction that
would reasonably be expected to impede, interfere with, delay, postpone, discourage, frustrate the
purposes of or adversely affect, or be inconsistent with, the Merger or the other transactions
contemplated by the Merger Agreement or the Voting Agreement or the performance by the Issuer of
its obligations under the Merger Agreement or by such Stockholder of its obligations under the
Voting Agreement.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In addition, each Stockholder irrevocably granted the Reporting Person, and any designee of
the Reporting Person, its irrevocable proxy to vote, express consent or dissent, or otherwise
exercise the voting power of such Stockholder&#146;s Covered Shares as indicated above.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Each Stockholder also agreed not to, directly or indirectly, (i)&nbsp;grant any proxies or powers
of attorney or other authorization or consent in or with respect to, or enter into any voting trust
or other agreement or arrangement with respect to, the voting of any Covered Shares, (ii)&nbsp;sell
(constructively or otherwise), assign, transfer, encumber or otherwise dispose of (including,
without limitation, by merger, by tendering into any tender or exchange offer, or otherwise), or
enter into any contract, option or other arrangement or understanding with respect to the direct or
indirect sale, assignment, transfer, encumbrance or other disposition of, any Covered Shares or
beneficial ownership thereof or therein, or (iii)&nbsp;take any action that would restrict or otherwise
affect the Stockholder&#146;s legal power, authority and right to comply with and perform its covenants
and obligations under the Voting Agreement, except in each case for certain exceptions provided in
the Voting Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In their capacity as stockholders of the Issuer, each Stockholder also agreed not to, and not
to authorize its representatives or affiliates to: (a)&nbsp;initiate, solicit, induce,
explore, or knowingly take any action to facilitate or encourage the submission or announcement of
any Acquisition Proposal, or any inquiries, proposals or offers that may reasonably be expected to
lead to an Acquisition Proposal, (b)&nbsp;enter into or participate in any discussions or negotiations
with, furnish any information relating to the Issuer or any of its subsidiaries or afford access to
any information or data relating to the Issuer or any of its subsidiaries or otherwise cooperate in
any way with, assist or facilitate any third party that is seeking to make, or has made, an
Acquisition Proposal, (c)&nbsp;enter into any agreement with respect to an Acquisition Proposal, (d)
solicit proxies or become a &#147;participant&#148; in a &#147;solicitation&#148; with respect to an Acquisition
Proposal (other than the Merger Agreement) or otherwise encourage or assist any party in taking or
planning any action that would reasonably be expected to compete with, restrain or otherwise serve
to interfere with or inhibit the timely consummation of the Merger in accordance with the terms of
the Merger Agreement, (e)&nbsp;initiate a shareholders&#146; vote or action by consent of the Issuer&#146;s
shareholders with respect to an Acquisition Proposal, or (f)&nbsp;become a member of a &#147;group&#148; with
respect to any voting securities of the Issuer that takes any action in support of an Acquisition
Proposal.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;An
&#147;Acquisition Proposal&#148; generally means, other than the transactions contemplated by the Merger Agreement, any third party offer, proposal, indication of interest or inquiry
contemplating or otherwise relating to any transaction or series of transactions involving (i)&nbsp;any
acquisition, lease, license or purchase, direct or indirect, of 20% or more of the consolidated
</DIV>




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</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">assets of the Issuer and its subsidiaries or 20% or more of any class of equity or voting
securities of the Issuer or any of its subsidiaries whose assets, individually or in the aggregate,
constitute 20% or more of the consolidated assets of the Issuer, (ii)&nbsp;any tender offer (including a
self-tender offer) or exchange offer that, if consummated, would result in any third party owning,
directly or indirectly, 20% or more of any class of equity or voting securities of the Issuer (or
any surviving or successor entity thereto) or any of its subsidiaries whose assets, individually or
in the aggregate, constitute 20% or more of the consolidated assets of the Issuer or (iii)&nbsp;a
merger, consolidation, share exchange, business combination, sale of substantially all the assets,
reorganization, recapitalization, liquidation, dissolution or other similar transaction involving
the Issuer or any of its subsidiaries whose assets, individually or in the aggregate, constitute
20% or more of the consolidated assets of the Issuer and its subsidiaries.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Voting Agreement will terminate upon the earlier to occur of (i)&nbsp;the effective time of the
Merger and (ii)&nbsp;the date of termination of the Merger Agreement in accordance with its terms. Each
Stockholder shall also have the right to terminate the Voting Agreement by written notice (within
five Business Days of the public announcement of the amendment giving rise to the right to
terminate) to the Reporting Person if the terms of the Merger Agreement are amended, modified or
waived without the written consent of such Stockholder to change the form or amount of the
consideration payable with respect to the Subject Shares pursuant to the Merger Agreement in a
manner adverse to such Stockholder.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The foregoing summaries of the Merger Agreement and the Voting Agreement do not purport to be
complete and are qualified in their entirety by reference to the complete text of such agreements
listed as Exhibits 1 and 2, respectively.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Other than as described above, the Reporting Person does not currently have any plans or
proposals which relate to, or may result in, any of the matters listed in Items 4(a)-(j) of
Schedule&nbsp;13D (although the Reporting Person reserves the right to develop such plans).
</DIV>
<!-- link2 "Item 5. Interest in Securities of the Issuer" -->

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;5. Interest in Securities of the Issuer</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The information set forth in Items 2, 3 and 4 is hereby incorporated herein by reference.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;and (b)&nbsp;Immediately prior to the execution of the Voting Agreement, the Reporting Person
did not beneficially own any shares of Common Stock. However, upon execution of the Voting
Agreement as of April&nbsp;27, 2011, under the definition of &#147;beneficial ownership&#148; as set forth in Rule
13d-3 under the Securities Exchange Act of 1934, as amended (the &#147;Exchange Act&#148;), the Reporting
Person may be deemed to have shared voting power with respect to (and therefore beneficially own)
12,890,313 shares of Common Stock, representing approximately 32.3% of the Common Stock
outstanding, on an as-converted basis, as of April&nbsp;27, 2011. Accordingly, the percentage of the
outstanding Common Stock that may be deemed to be beneficially owned by the Reporting Person is
approximately 32.3%.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Except as set forth above, neither the Reporting Person nor, to the best of the Reporting
Person&#146;s knowledge, any of the individuals named in Schedule&nbsp;I hereto, has power to vote or to
direct the vote or to dispose or direct the disposition of any shares of Common Stock.
</DIV>

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</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Reporting Person disclaims beneficial ownership of any Common Stock. Neither the filing
of this Schedule&nbsp;13D nor any of its contents shall be deemed to constitute an admission that the
Reporting Person is the beneficial owner of the Common Stock referred to herein for purposes of
Section 13(d) of the Exchange Act or for any other purpose, and such beneficial ownership is
expressly disclaimed.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Except as set forth in this Item&nbsp;5, to the best knowledge of the Reporting Person, neither
the Reporting Person nor any person listed in Schedule&nbsp;I hereof has beneficial ownership of, or has
engaged in any transaction during the past 60&nbsp;days in, any shares of Common Stock.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;Except as set forth in this Schedule&nbsp;13D, to the best knowledge of the Reporting Person,
neither the Reporting Person nor any person listed in Schedule&nbsp;I hereof has the right to receive
dividends from, or the proceeds from the sale of, the shares of Common Stock referred to in this
Item&nbsp;5.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e)&nbsp;Not applicable.
</DIV>
<!-- link2 "Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer" -->

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the
Issuer</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Except as set forth in Item&nbsp;4 of this Schedule&nbsp;13D, to the best knowledge of the Reporting
Person, there are no other contracts, arrangements, understandings or relationships (legal or
otherwise) among the Reporting Person and the individuals named in Schedule&nbsp;I and between such
persons and any other person with respect to any securities of the Issuer, including, but not
limited to, transfer or voting of any securities, finder&#146;s fees, joint ventures, loan or option
arrangements, puts or calls, guarantees of profits, division of profits or losses, or the giving or
withholding of proxies.
</DIV>
<!-- link2 "Item 7. Material to Be Filed as Exhibits" -->

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;7. Material to Be Filed as Exhibits</B>
</DIV>

<DIV align="center">
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<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" colspan="3" style="border-bottom: 1px solid #000000">Exhibit</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000">Description</TD>
</TR>

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    <TD align="right" valign="top">1</TD>
    <TD nowrap valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Agreement and Plan of Merger, dated as of April&nbsp;27, 2011, by and
among CoStar Group, Inc., Lonestar Acquisition Sub, Inc. and
LoopNet, Inc. (incorporated herein by reference to Exhibit&nbsp;2.1 to
CoStar Group, Inc.&#146;s Current Report on Form&nbsp;8-K dated April&nbsp;28,
2011)</DIV></TD>
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</TR>
<TR valign="bottom">
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    <TD align="right" valign="top">2</TD>
    <TD nowrap valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Voting and Support Agreement, dated as of April&nbsp;27, 2011, by and
among the CoStar Group, Inc., LoopNet, Inc., the holders of Series
A convertible preferred stock of LoopNet, Inc., certain executive
officers and directors of LoopNet, Inc., (incorporated herein by
reference to Exhibit&nbsp;10.1 to CoStar Group Inc.&#146;s Current Report on
Form&nbsp;8-K dated April&nbsp;28, 2011)</DIV></TD>
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</TD>
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<DIV align="center" style="font-size: 10pt; margin-top:18pt">SIGNATURE</div>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After reasonable inquiry and to the best of my knowledge and belief, I certify that the
information set forth in this statement is true, complete and correct.
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Dated: May&nbsp;6, 2011
</DIV>

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<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="49%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="14%">&nbsp;</TD>
</TR>
<TR></TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top">Signature:</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><B>COSTAR GROUP, INC.</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Brian J. Radecki
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Brian J. Radecki
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chief Financial Officer</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U><B>SCHEDULE I</B></U>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>CoStar Group, Inc.<BR>
Directors and Executive Officers</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Except as indicated below, each person&#146;s business address is c/o CoStar Group, Inc., 1331 L
Street, NW, Washington, DC 20005, and each such person is a United States citizen.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="35%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="60%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Name</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Present Principal Occupation</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>Directors</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Michael R. Klein
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chairman of the Board; Chairman, The Sunlight Foundation</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Andrew C. Florance
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chief Executive Officer and President</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">David Bonderman
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Founding Partner, TPG Capital, L.P.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Michael J. Glosserman
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Managing Member, the JBG Companies</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Warren H. Haber
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chairman of the board &#038; CEO, Founders Equity Inc.;
Managing General Partner of FEF Management Services,
LLC</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Christopher J. Nassetta
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">CEO &#038; President, Hilton Worldwide</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Josiah O. Low, III
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Senior Advisor to Catterton Partners L.P., Director,
Rosetta Resources, Inc.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">

<TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>Executive Officers (Who Are Not Directors)</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Brian J. Radecki
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chief Financial Officer</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">John Stanfill
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Senior Vice President of Sales and Customer Service</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Jennifer L. Kitchen
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Senior Vice President of Research</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Paul Marples
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Managing Director, CoStar UK Limited. Mr.&nbsp;Marples is a
citizen of the United Kingdom</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U><B>SCHEDULE II</B></U>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>Stockholders</B>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Calera Capital Partners IV, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Calera Capital Partners IV Side-By-Side, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Trinity Ventures IX, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Trinity IX Side-By-Side Fund, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Trinity IX Entrepreneurs Fund, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Saints Rustic Canyon, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Rustic Canyon Ventures III, L.P.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The Board of Trustees of The Leland Stanford Junior University (SBST)</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Richard J. Boyle, Jr.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Thomas P. Byrne</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Brent Stumme</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Jason Greenman</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Wayne Warthen</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>William Byrnes</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Dennis Chookaszian</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>James T. Farrell</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Noel Fenton</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Scott Ingraham</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>&#149;</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Thomas E. Unterman</TD>
</TR>





</TABLE>
</DIV>
<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV style="margin-top: 6pt"><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">



</TABLE>
</DIV>
<!-- link1 "INDEX TO EXHIBITS" -->
<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>INDEX TO EXHIBITS</B>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="3%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="88%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" colspan="3"><B>Exhibit</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="left">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" colspan="3" style="border-bottom: 1px solid #000000"><B>Number</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Description of Exhibits</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">1</TD>
    <TD nowrap valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Agreement and Plan of Merger, dated as of April&nbsp;27, 2011,
by and among CoStar Group, Inc., Lonestar Acquisition Sub,
Inc. and LoopNet, Inc. (incorporated herein by reference to
Exhibit&nbsp;2.1 to CoStar Group, Inc.&#146;s Current Report on Form
8-K dated April&nbsp;28, 2011)</DIV></TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
</TR>
<TR valign="bottom">
    <TD nowrap align="right" valign="top">&nbsp;</TD>
    <TD align="right" valign="top">2</TD>
    <TD nowrap valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Voting and Support Agreement, dated as of April&nbsp;27, 2011,
by and among the CoStar Group, Inc., LoopNet, Inc., the
holders of Series&nbsp;A convertible preferred stock of LoopNet,
Inc., certain executive officers and directors of LoopNet,
Inc., (incorporated herein by reference to Exhibit&nbsp;10.1 to
CoStar Group Inc.&#146;s Current Report on Form&nbsp;8-K dated April
28, 2011)</DIV></TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>



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