Information about Geographic Areas (Tables)

6 Months Ended

Jun. 30, 2012

Information about Geographic Areas [Abstract]

Revenues by geographic area, based on billing location of customer

Long-lived assets by geographic area were as follows (in thousands):

	June 30,
	2012		2011
North America	$	26,375	$	7,859
Europe		7,788		1,391
Asia Pacific and other		1,289		217
Total long-lived assets	$	35,452	$	9,467

Long-lived assets by geographic area

The fair value of each stock option grant and stock purchase right granted under the ESPP was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions and fair value per share:

	Three Months Ended June 30,		Six Months Ended June 30,
	2012	2011	2012	2011
Stock Options:
Expected volatility	54% - 55%	50% - 56%	54% - 57%	50% - 69%
Expected term (in years)	6.04	6.07	6.04	6.06
Risk-free interest rate	0.90% - 1.17%	1.71% - 2.23%	0.90% - 1.18%	1.69% - 2.67%
Dividend yield	—  %	—  %	—  %	—  %

	Three and Six Months Ended
	June 30, 2012
ESPP:
Expected volatility		41.58	%
Expected term (in years)		0.58
Risk-free interest rate		0.16	%
Dividend yield		—	%