Net Loss per Share (Tables)

6 Months Ended

Jun. 30, 2013

Schedule of computation of basic and diluted net loss per share of common stock

The following table sets forth the computation of the Company's basic and diluted net loss per share of common stock under the two-class method attributable to common stockholders during the years ended December 31, 2010, 2011, 2012 and the six months ended June 30, 2012 and 2013:

	Year ended December 31,									Six Months Ended June 30,

	2010			2011			2012			2012			2013
	(in thousands, except per share data)
										(unaudited)
Numerator:
Net loss	$	(11,817	)	$	(22,606	)	$	(34,385	)	$	(16,583	)	$	(21,914	)

Denominator:
Weighted-average common shares outstanding		2,338			2,489			2,934			2,797			11,725
Less: Weighted-average unvested common shares subject to repurchase or forfeiture		(366	)		(215	)		(128	)		(142	)		(253	)

Weighted-average shares used in computing net loss per share of common stock, basic and diluted		1,972			2,274			2,806			2,655			11,472

Net loss per share of common stock, basic and diluted	$	(5.99	)	$	(9.94	)	$	(12.26	)	$	(6.25	)	$	(1.91	)

Schedule of potentially dilutive securities excluded from the diluted per share calculation

Potentially dilutive securities that were excluded from the diluted per share calculation because they would have been antidilutive were as follows:

	Year Ended December 31,						Six Months Ended June 30,

	2010		2011		2012		2012		2013
							(unaudited)
Convertible preferred stock		21,245,808		25,033,684		25,876,142		25,876,142		—
Stock options to purchase common stock		2,350,977		4,587,344		6,581,481		6,372,867		7,891,581
Employee stock purchase plan		—		—		—		—		282,769
Common stock held in escrow		—		—		11,872		11,872		—
Common stock subject to repurchase		349,684		226,688		148,060		127,901		197,211
Restricted stock units		—		—		328,466		306,219		256,635

		23,946,469		29,847,716		32,946,021		32,695,001		8,628,196