Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
Cash flows from operating activities:
Net income (loss)	$ (27,417)		$ 5,148
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	8,842		1,794
Amortization of premiums on short-term investments, net	594
Amortization of deferred commissions	9,264		3,942
Stock-based compensation	18,588		4,224
Tax benefit from exercise of stock options	(533)		(21)
Bad debt expense	148
(Gain) loss on disposal of property and equipment	(1)		60
Lease abandonment costs	2,922
Changes in operating assets and liabilities:
Accounts receivable	(11,065)		(7,768)
Deferred commissions	(20,525)		(6,419)
Prepaid expenses and other current assets (1)	4,242	[1]	(2,092)
Other assets	(35)		(268)
Accounts payable	(106)		1,866
Accrued expenses and other current liabilities	4,644		4,239
Deferred rent	(2,957)		3,153
Deferred revenue	43,081		28,589
Other long-term liabilities	2,409		(6)
Net cash provided by operating activities	32,095		36,441
Cash flows from investing activities:
Purchases of property and equipment	(32,156)		(9,193)
Purchases of short-term investments	(146,922)
Sale of short-term investments	1,025
Maturities of short-term investments	5,800
Restricted cash	8		150
Net cash used in investing activities	(172,245)		(9,043)
Cash flows from financing activities:
Net proceeds from initial public offering	169,799
Proceeds from exercise of stock options	2,349		1,309
Proceeds from early exercise of stock options	1,024		1,457
Tax benefit from exercise of stock options	533		21
Net proceeds from issuance of common stock	17,848
Purchases of common stock and restricted stock from stockholders	(1,960)
Net cash provided by financing activities	189,593		2,787
Foreign currency effect on cash and cash equivalents	(555)		394
Net increase in cash and cash equivalents	48,888		30,579
Cash at beginning of period	68,088		38,457
Cash and cash equivalents at end of period	116,976		69,036
Supplemental disclosures of other cash flow information:
Interest paid	3		4
Taxes paid	1,241		1,758
Non-cash investing and financing activities:
Property and equipment included in accounts payable and accrued expenses	3,768		1,785
Vesting of early exercised stock options	1,287		109
Accretion of preferred stock dividends and issuance costs	308		471
Deferred offering costs not yet paid	$ 15

[1] Includes $5.3 million payment received from the Company's founder during the nine months ended September 30, 2012. Refer to Note 8.