Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2012

Net Loss Per Share

Schedule of basic and diluted net loss per share

Basic and diluted net loss per share is calculated as follows (in thousands, except share and per share amounts):

	Year Ended December 31,
	2012			2011			2010
Numerator:
Net loss	$	(69,128	)	$	(42,476	)	$	(14,630	)
Extinguishment of preferred stock		—			60,937			—
Accretion of preferred stock		(13,992	)		(10,933	)		(12,143	)
Earnings attributable to participating preferred stockholders		—			(7,275	)		—
Earnings (loss) attributable to common stockholders—basic		(83,120	)		253			(26,773	)
Effect of dilutive convertible preferred stock		—			—			—
Earnings (loss) attributable to common stockholders—diluted	$	(83,120	)	$	253		$	(26,773	)
Denominator:
Weighted-average number of common shares used in (loss) earnings per share—basic		839,698			499,944			320,942
Effect of dilutive options to purchase common stock		—			464,933			—
Effect of dilutive convertible preferred stock		—			2,489,399			—
Weighted-average number of common shares used in (loss) earnings per share—diluted		839,698			3,454,276			320,942
(Loss) earnings per share—basic	$	(98.99	)	$	0.51		$	(83.42	)
Effect of dilutive options to purchase common stock		—			(0.24	)		—
Effect of dilutive convertible preferred stock		—			(0.20	)		—
(Loss) earnings per share—diluted	$	(98.99	)	$	0.07		$	(83.42	)

Schedule of potentially dilutive securities excluded from the computation of diluted weighted-average shares outstanding

	Year Ended December 31
	2012		2011		2010
Convertible preferred stock		4,834,687		5,419,946		11,808,290
Options to purchase common stock		3,890,911		894,160		1,461,865
Warrants		15,000		8,860		1,333