Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2012

Stockholders' Equity [Abstract]

Schedule of weighted average Black-Scholes model assumptions

The weighted average Black-Scholes model assumptions for the three and nine months ended September 30, 2012 and 2011 were as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2012			2011			2012			2011
Expected term (in years)		5.0			5.1			5.1			5.3
Expected volatility		46	%		45.0	%		46	%		51	%
Risk-free interest rate		0.67	%		0.90	%		0.78	%		1.65	%
Expected dividend yield		—			—			—			—

Reconciliation of option and restricted stock activity

Option and restricted stock activity under the Company’s Plans for the nine months ended September 30, 2012 were as follows: (shares in thousands):

				Options Outstanding					Restricted Stock Outstanding
	Shares and Units Available for Grant			Number of Shares			Weighted- Average Exercise Price		Number of Shares
Outstanding — December 31, 2011		6,409			15,335		$	5.70		802
Additional shares reserved under the 2012 equity incentive plan		2,903			—			—		—
Granted		(4,317	)		2,115			14.98		2,202
Options exercised/ Restricted stock released		—			(2,053	)		3.86		(148	)
Forfeited		882			(750	)		9.00		(132	)
Outstanding — September 30, 2012		5,877			14,647					2,724

Summary of stock-based compensation expense

The following table summarizes the consolidated stock-based compensation expense by line item in the Condensed Consolidated Statements of Operations (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2012		2011		2012		2011
Cost of revenue	$	763	$	470	$	2,050	$	1,286
Sales and marketing		2,180		1,111		5,836		2,981
Research and development		562		327		1,455		864
General and administrative		2,148		1,060		5,919		2,973
Total stock-based compensation	$	5,653	$	2,968	$	15,260	$	8,104

Estimated fair value of purchase rights under the Employee stock purchase plan using Black-Scholes valuation model

The fair value of each purchase right under the ESPP was estimated on the date of grant using the Black-Scholes option valuation model and the straight-line attribution approach with the following weighted-average assumptions:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2012			2011			2012			2011
Expected term (in years)		0.50			0.50			0.50			0.39
Expected volatility		45	%		45	%		45	%		36	%
Risk-free interest rate		0.14	%		0.07	%		0.14	%		0.18	%
Expected dividend yield		—			—			—			—