Stock Awards (Tables)

6 Months Ended

Jun. 30, 2012

Stock Awards [Abstract]

Summary of stock option activity

A summary of the restricted stock activity for the six months ended June 30, 2012 is as follows:

	Number of Shares			Weighted- Average Grant Date Fair Value
Outstanding at December 31, 2011		578,616		$	1.21
Early exercised		263,970			2.38
Vested		(367,399	)		1.30
Repurchased		(2,084	)		0.11
Outstanding at June 30, 2012		473,103		$	1.80

Summary of the restricted stock activity

The following tables present the calculation of basic and diluted net income (loss) per share attributable to common stockholders (in thousands, except share and per share data):

	Three Months Ended June 30,						Six Months Ended June 30,
	2012			2011			2012			2011
Numerator:
Net income (loss)	$	(8,724	)	$	2,036		$	(14,364	)	$	5,027
Accretion of redeemable convertible preferred stock		(154	)		(158	)		(308	)		(314	)
Net income attributable to participating securities		—			(1,520	)		—			(3,835	)
Net income (loss) attributable to common stockholders - Basic	$	(8,878	)	$	358		$	(14,672	)	$	878
Undistributed earnings reallocated to participating securities	$	—		$	133		$	—		$	331
Net income (loss) attributable to common stockholders - Diluted	$	(8,878	)	$	491		$	(14,672	)	$	1,209
Denominator:
Weighted-average shares outstanding - Basic		27,788,547			19,668,851			26,452,100			19,188,210
Effect of potentially dilutive securities:
Common stock options		—			9,915,374			—			9,745,364
Weighted-average shares outstanding - Diluted		27,788,547			29,584,225			26,452,100			28,933,574
Net income (loss) per share attributable to common stockholders:
Basic	$	(0.32	)	$	0.02		$	(0.55	)	$	0.05
Diluted	$	(0.32	)	$	0.02		$	(0.55	)	$	0.04