Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2014

Earnings Per Share Attributable to Common Stockholders

Computation of basic and diluted net loss per share attributable to common stockholders

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2014		2013		2014		2013
Net loss	$	(15,034)	$	(3,802)	$	(24,955)	$	(12,825)
Weighted-average common shares outstanding		67,784		58,313		63,962		57,231
Net loss per share - basic and diluted	$	(0.22)	$	(0.07)	$	(0.39)	$	(0.22)

Anti-dilutive shares excluded from the calculation of diluted net loss per share

:

	June 30,
	2014	2013
Options to purchase common stock	26,665	16,078
Common stock warrants	3,981	5,251
Conversion of convertible preferred stock	—	2,857
Unvested restricted stock awards	741	95
Contingently redeemable shares	—	189
Total shares excluded from net loss per share	31,387	24,470