Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2013

Reconciliation of Option and Restricted Stock Activity

Option and restricted stock activity under the 2011 Plan for the six months ended June 30, 2013 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, 2012	4,024		15,189		$	6.98	3,928
Additional shares reserved under the 2011 equity incentive plan	3,025		—		—		—
Granted	(3,910	)	2,093		7.05		1,817
Options exercised/ Restricted stock released	—		(2,951	)	7.36		(405	)
Canceled/Forfeited	4,469		(3,793	)	6.65		(676	)
Outstanding — June 30, 2013	7,608		10,538		5.30		4,664

Summary of Stock-Based Compensation Expense

The following table summarizes the consolidated stock-based compensation expense included in the condensed consolidated statements of operations (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Cost of revenue	$	688	$	715	$	1,420	$	1,287
Sales and marketing	2,449		1,982		4,982		3,656
Research and development	519		530		1,005		893
General and administrative	1,767		2,133		3,936		3,771
Total stock-based compensation	$	5,423	$	5,360	$	11,343	$	9,607

Stock Option Plan

Weighted Average Black-Scholes Model Assumptions

The weighted average Black-Scholes model assumptions for the three and six months ended June 30, 2013 and 2012 were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Expected term (in years)	5.0		5.1		5.0		5.1
Expected volatility	44	%	45	%	44	%	45	%
Risk-free interest rate	0.84	%	0.83	%	0.85	%	0.82	%
Expected dividend yield	—		—		—		—

Employee Share Purchase Plan

Weighted Average Black-Scholes Model Assumptions

Black-Scholes option valuation model and the straight-line attribution approach with the following weighted-average assumptions:

	Three Months Ended June 30, 2013		Three Months Ended June 30, 2012		Six Months Ended June 30, 2013		Six Months Ended June 30, 2012
Expected term (in years)	0.50		0.50		0.50		0.50
Expected volatility	27	%	45	%	27	%	45	%
Risk-free interest rate	0.13	%	0.13	%	0.13	%	0.13	%
Expected dividend yield	—		—		—		—