Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net loss	$ (21,914)	$ (16,583)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,787	650
Stock-based compensation expense	3,617	1,234
Changes in operating assets and liabilities:
Accounts receivable, net	(2,856)	(3,333)
Prepaid expenses and other current assets	(1,233)	71
Other assets	(183)	(740)
Accounts payable	2,606	(1,124)
Accrued expenses and other current liabilities	3,087	2,520
Deferred revenue	9,932	5,733
Deferred rent	86	(27)
Net cash used in operating activities	(5,071)	(11,599)
Cash flows from investing activities:
Purchase of property and equipment	(5,863)	(2,382)
Capitalized software development	(221)
Cash acquired in acquisition		698
Net cash used in investing activities	(6,084)	(1,684)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discount	80,506
Proceeds from private placement	6,500
Proceeds from issuance of common stock upon exercise of stock options	1,416	413
Repurchase of unvested common stock from terminated employees	(16)	(50)
Proceeds from issuance of debt	3,089	1,100
Repayment of debt	(116)
Payment of deferred initial public offering costs	(2,537)
Net cash provided by financing activities	88,842	1,463
Effect of foreign exchange rate changes on cash and cash equivalents	(52)	83
Net increase (decrease) in cash and cash equivalents	77,635	(11,737)
Cash and cash equivalents - beginning of period	44,247	67,400
Cash and cash equivalents -end of period	121,882	55,663
Supplemental disclosures of cash flow information:
Cash paid for interest	69
Cash paid for income taxes	28
Supplemental disclosure of noncash investing and financing activities:
Conversion of convertible preferred stock into common stock	119,121
Vesting of early exercise options	410	137
Property and equipment acquired through tenant improvement allowance	$ 1,136