v2.4.0.6
Employee Stock and Benefit Plans (Tables)
9 Months Ended
Sep. 30, 2012
Employee Stock and Benefit Plans [Abstract]  
Stock-based employee compensation
Stock-based employee compensation is included in the condensed consolidated statements of income as follows:

Three Months Ended
 
Nine Months Ended
 
September 30,
 
September 30,
 
2012
 
2011
 
2012
 
2011
 
(in thousands)
Cost of revenues
$
68

 
$
44

 
$
191

 
$
94

Research and development
167

 
118

 
461

 
334

Sales and marketing
306

 
173

 
746

 
399

General and administrative
244

 
204

 
723

 
603

Total stock-based employee compensation
$
785

 
$
539

 
$
2,121

 
$
1,430

Fair value assumptions of options granted to employees
The fair value of each option granted to employees is estimated on the date of grant using the Black-Scholes option-pricing model based on the following assumptions:
 
Three Months Ended
 
Nine Months Ended
 
September 30,
 
September 30,
 
2012
 
2011
 
2012
 
2011
Expected term (in years)
5.3 - 6.0
 
5.6
 
5.3 - 6.0
 
5.6
Volatility
53%
 
55%
 
53%
 
55%
Risk-free interest rate
0.6% - 0.7%
 
1.0% - 1.6%
 
0.6% - 0.8%
 
1.0% - 2.3%
Dividend yield
 
 
 
Stock option activity
A summary of the Company’s stock option activity is as follows:
 
Outstanding Shares
 
Weighted Average Exercise Price
 
Weighted Average Remaining Contractual Life (Years)
 
Aggregate Intrinsic Value
 
 
 
 
 
 
 
(in thousands)
Balance as of December 31, 2011
6,312,041

 
$
3.36

 
6.9
 
$
16,012

Granted
1,322,906

 
8.39

 
 
 
 
Exercised
(703,459
)
 
2.84

 
 
 
 
Canceled
(392,389
)
 
6.85

 
 
 
 
Balance as of September 30, 2012
6,539,099

 
4.23

 
7.0
 
$
64,953

Vested and expected to vest - September 30, 2012
6,100,152

 
4.00

 
6.9
 
 
Exercisable - September 30, 2012
6,537,727

 
4.23

 
7.0