Net Income (Loss) Per Share Attributable to Common Stockholders (Tables)

9 Months Ended

Sep. 30, 2012

Net Income (Loss) Per Share Attributable to Common Stockholders [Abstract]

Calculation of basic and diluted net income (loss) per share attributable to common stockholders

	Three Months Ended  September 30,						Nine Months Ended  September 30,
	2012			2011			2012			2011
Numerator:
Net income (loss)	$	(13,053	)	$	121		$	(27,417	)	$	5,148
Accretion of redeemable convertible preferred stock		0			(157	)		(308	)		(471	)
Net income attributable to participating securities		—			—			—			(3,788	)
Net income (loss) attributable to common stockholders - Basic	$	(13,053	)	$	(36	)	$	(27,725	)	$	889
Undistributed earnings reallocated to participating securities	$	—		$	26		$	—		$	361
Net income (loss) attributable to common stockholders - Diluted	$	(13,053	)	$	(10	)	$	(27,725	)	$	1,250
Denominator:
Weighted-average shares outstanding - Basic		117,698,005			20,693,359			57,089,411			19,695,440
Effect of potentially dilutive securities:
Common stock options		—			11,433,176			—			10,917,099
Weighted-average shares outstanding - Diluted		117,698,005			32,126,535			57,089,411			30,612,539
Net income (loss) per share attributable to common stockholders:
Basic	$	(0.11	)	$	—		$	(0.49	)	$	0.05
Diluted	$	(0.11	)	$	—		$	(0.49	)	$	0.04

Summary of potentially dilutive securities

	Three Months Ended September 30,				Nine Months Ended September 30,
	2012		2011		2012		2011
Common stock options		37,279,442		14,246,439		37,279,442		8,548,888
Convertible preferred stock		—		83,703,016		—		83,703,016
Restricted stock units		1,134,851		—		1,134,851		—
Common stock subject to repurchase		349,165		524,167		349,165		288,350
ESPP obligations		468,704		—		468,704		—
Total potentially dilutive securities		39,232,162		98,473,622		39,232,162		92,540,254