Stock-based Compensation and Awards (Tables)

9 Months Ended

Sep. 30, 2014

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

Rollforward of stock option activity

A summary of the stock option activity for the nine months ended September 30, 2014 is presented below:

	Options outstanding
	Number of Options		Weighted Average Exercise Price		Weighted average remaining contractual term	Aggregate intrinsic value
					(in years)	(in thousands)
Outstanding at December 31, 2013	3,287,207		$	9.62	6.45	$	24,880
Options granted	972,734		11.85
Options exercised	(246,456	)	3.55
Options canceled	(353,454	)	14.25
Outstanding at September 30, 2014	3,660,031		$	10.17	6.20	$	8,265

Stock option valuation assumptions

The following assumptions were used for each respective period for employee stock options:

	Three months ended September 30,		Nine months ended September 30,
	2014	2013	2014	2013
Expected Term (in years)	5.45	5.38	5.41 - 5.45	5.38 - 5.43
Volatility	41.4%	46.7%	44.0% - 48.2%	46.7% - 48.1%
Risk-free interest rate	1.78%	1.80%	1.59% - 1.78%	0.81% - 1.80%
Dividend yield	0%	0%	0%	0%

Equity B-S-M Valuation Assumptions

The following Black-Scholes option-pricing assumptions were used for each respective period for the ESPP:

	Three months ended September 30,		Nine months ended September 30,
	2014	2013	2014	2013
Expected Term (in years)	0.50	0.25	0.50	0.25 - 0.50
Volatility	35.9%	33.3%	35.9% - 36.0%	33.3%
Risk-free interest rate	0.05%	0.05%	0.05% - 0.10%	0.05% - 0.13%
Dividend yield	0%	0%	0%	0%

Rollforward of RSA and RSU activty

A summary of restricted stock and RSU activity for the nine months ended September 30, 2014 is presented below:

	Restricted Stock Awards				Restricted Stock Units
	Number of shares		Weighted Average Grant Date Fair Value per Share		Number of shares		Weighted Average Grant Date Fair Value per Share
Outstanding at December 31, 2013	12,076		$	12.42	755,271		$	19.24
Granted	—		—		769,262		11.87
Vested	(12,076	)	12.42		(269,443	)	18.97
Forfeited	—		—		(144,776	)	17.25
Outstanding at September 30, 2014	—		$	—	1,110,314		$	14.46

Allocation of Recognized Period Costs

The following table presents the stock-based compensation allocation of expense (both for employees and non-employees):

	Three months ended September 30,				Nine months ended September 30,
(in thousands)	2014		2013		2014		2013
Cost of revenue	$	320	$	272	$	857	$	707
Research and development	266		194		725		632
Sales and marketing	1,123		816		3,158		2,121
General and administrative	1,076		1111		3,420		2,653
Total stock-based compensation	$	2,785	$	2,393	$	8,160	$	6,113