Net Loss Per Share Available to Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Abstract]

Calculation of Basic and Diluted Net Loss Per Share

The following table presents the calculation of basic and diluted net loss per share:

	Three Months Ended March 31,
	2013			2012
Numerator:
Net loss	$	(10,501	)	$	(6,754	)
Denominator:
Weighted average number of shares, basic and diluted		7,365			4,254
Net loss per share available to common stockholders
Basic and diluted net loss per common share available to common stockholders	$	(1.43	)	$	(1.59	)

Potential Common Shares Outstanding

The following table presents the potential common shares outstanding that were excluded from the computation of diluted net loss per share available to common stockholders for the periods presented because including them would have been anti-dilutive:

	Three Months Ended March 31,
	2013		2012
Convertible preferred stock		—		17,275
Options to purchase common stock		5,046		3,025
Common stock subject to repurchase		302		287
Convertible preferred stock warrants		—		51
Common stock warrants		114		37
		5,462		20,675