Stock-Based Awards (Tables)

9 Months Ended

Sep. 30, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock Option Activity

The following table summarizes the stock option activity for the nine months endedSeptember 30, 2012 (in thousands, except per share and term information):

	Shares		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding, December 31, 2011	5,475		$	6.04	8.3	$	66,817
Granted	2,188		$	20.90	9.6
Exercised	(907	)	$	1.96	6.0
Forfeited	(218	)	$	13.93
Outstanding, September 30, 2012	6,538		$	11.31	8.4	$	126,493

	Shares	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value
Exercisable at December 31, 2011	2,233	$	2.24	7.2	$	35,742
Vested and expected to vest at December 31, 2011	5,262	$	5.83	8.2	$	65,328
Exercisable at September 30, 2012	2,339	$	4.92	7.3	$	60,207
Vested and expected to vest at September 30, 2012	6,459	$	11.29	8.4	$	125,080

Stock-Based Compensation Expense Related to Stock Options and Restricted Stock Units

Stock-based compensation expense related to stock options, restricted stock and restricted stock units is included in the following line items in the accompanying Consolidated Statement of Operations for the three and nine months endedSeptember 30, 2012 and 2011 (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2012		2011		2012		2011
Cost of revenue	$	294	$	75	$	1,305	$	176
Sales and marketing expense	1,118		355		2,244		825
Research and development expense	258		133		598		613
General and administrative expense	1,646		457		4,150		1,345
Total	$	3,316	$	1,020	$	8,297	$	2,959