NET LOSS PER SHARE

12 Months Ended

Dec. 31, 2012

NET LOSS PER SHARE

NOTE 2 — NET LOSS PER SHARE

The Company computes basic net loss per share by dividing its net loss for the period by the weighted average number of common shares outstanding during the period less the weighted average unvested common shares subject to restrictions by the Company.

	Year Ended December 31,
	2012			2011			2010
Net loss	$	(20,459	)	$	(21,101	)	$	(13,423	)
Basic and diluted shares:
Weighted average common shares outstanding		64,932			57,834			35,439
Weighted average unvested common shares subject to restrictions		(614	)		(316	)		—
Weighted average shares used to compute basic and diluted net loss per share		64,318			57,518			35,439
Net loss per share — basic and diluted	$	(0.32	)	$	(0.37	)	$	(0.38	)

The following weighted average options and warrants to purchase common stock and unvested shares of common stock subject to restrictions have been excluded from the computation of diluted net loss per share of common stock for the periods presented because including them would have had an anti-dilutive effect:

	Year Ended December 31,
	2012		2011		2010
Warrants to purchase common stock		4,187		5,344		2,435
Unvested common shares subject to restrictions		614		316		—
Options to purchase common stock		10,321		8,112		6,347
		15,122		13,772		8,782