Stock-Based Awards

9 Months Ended

Sep. 30, 2012

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

Stock-Based Awards

STOCK-BASED AWARDS

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

Unrecognized compensation expense relating to stock options was $29.4 million at September 30, 2012, which is expected to be recognized over a weighted-average period of 2.7 years.

The aggregate grant date fair value of stock options granted for the nine months endedSeptember 30, 2012 was $23.1 million.

Restricted Stock

In connection with the acquisition of Sonar, the Company issued 31,164 restricted shares of its common stock, valued at approximately $0.7 million, to certain Sonar shareholders who also became employees of the company post-acquisition. The vesting of the restricted shares is subject to continued employment, and the fair value of the restricted shares will be recognized as a post-acquisition compensation expense over the 2 year vesting period (see Note 2).

Restricted Stock Units

At September 30, 2012, 521,178 of non-vested restricted stock units were outstanding. Unrecognized compensation expense related to non-vested restricted stock units was $5.2 million at September 30, 2012, which is expected to be recognized into expense over the weighted-average period of 2.2 years.

Stock-Based Compensation

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