Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2014

Summary of Assumptions Used to Estimate the Fair Value of Stock Options

The fair value of each stock option is estimated on the date of grant for the periods presented using the Black-Scholes model based on the following assumptions:

	Six Months Ended June 30,
	2014		2013
Expected life (in years)		6.08		6.08
Risk-free interest rate		2.33%		1.09%
Volatility		55%		51%
Dividend yield	—		—

Summary of Stock Option and Restricted Stock Units Award Activity

A summary of the Company’s stock option and RSUs award activity under the Plan is as follows:

				Options Outstanding									RSUs Outstanding
	Shares Available for Grant			Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (inthousands)		Number of Shares			Weighted Average Grant Date Fair Value
Balance as of December 31, 2013		2,035,282			12,635,707		$	5.87		7.02	$	68,944		4,521,191		$	5.59
Increase in shares authorized		4,000,000
Options granted		(46,875	)		46,875			16.00
Options exercised		—			(1,430,239	)		2.12				11,912
Options canceled or expired		29,802			(29,802	)		6.49
RSUs granted		(3,106,663	)											3,106,663			17.95
RSUs canceled or expired		282,777												(282,777	)		8.84
Balance as of June 30, 2014		3,194,323			11,222,541			6.39		6.80		223,590		7,345,077			10.70
Vested and expected to vest as of    June 30, 2014					10,546,146			6.10		6.69		213,241
Vested and exercisable as of    June 30, 2014					7,163,304			3.25		5.69		165,160

Schedule of Stock Based Compensation Expense

The following table sets forth the total stock-based compensation expense resulting from RSUs, stock options and ESPP included in the Company’s condensed consolidated statements of operations (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2014		2013		2014		2013
Cost of revenues	$	523	$	85	$	2,100	$	171
Sales and marketing		1,284		322		5,401		704
Research and development		1,760		271		7,270		571
General and administrative		3,094		390		6,482		1,108
Total stock-based compensation expense	$	6,661	$	1,068	$	21,253	$	2,554

Employee Stock Purchase Plan

Summary of Assumptions Used to Estimate the Fair Value of Stock Options

The fair value of the option feature is estimated using the Black-Scholes model for the period presented based on the following assumptions:

	Six Months Ended June 30, 2014
Expected life (in years)		0.62
Risk-free interest rate		0.08%
Volatility		55%
Dividend yield	—