(11) Intangible Assets from Acquisitions

Intangible assets from acquisitions consisted of the following (in thousands):


	As of December 31, 2012
	Gross Carrying Amount		Accumulated Amortization(1)			Net
Advertiser relationship	$	3,070	$	(2,125	)	$	945
Distribution partner relationship		4,830		(2,787	)		2,043
Acquired technology		2,760		(2,388	)		372

	$	10,660	$	(7,300	)	$	3,360


	As of September 30, 2013
	Gross Carrying Amount		Accumulated Amortization(1)			Net
Advertiser relationship	$	3,070	$	(3,046	)	$	24
Distribution partner relationship		4,830		(3,994	)		836

	$	7,900	$	(7,040	)	$	860

(1)	Excludes the original cost and accumulated amortization of fully-amortized intangible assets which were $82.1 million and $84.7 million at December 31, 2012 and September 30, 2013, respectively.

Amortizable intangible assets are amortized on a straight-line basis over their useful lives. Amortization expense incurred by the Company was approximately $1.1 million and $709,000 for the three months ended September 30, 2012 and 2013, respectively, and was $3.7 million and $2.5 million for the nine months ended September 30, 2012 and 2013, respectively. Based upon the current amount of intangible assets subject to amortization, the estimated amortization expense for the next five years is as follows: $427,000 for the remainder of 2013, $433,000 in 2014, and $0 thereafter.