Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Operating activities
Net loss	$ (18,539)	$ (5,536)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense	1,713	665
Stock-based expense	12,338	1,558
Bad debt expense	153	192
Excess tax benefit related to stock options	82
Changes in operating assets and liabilities:
Accounts receivable	1,129	(1,249)
Prepaid expenses and other current assets	442	605
Other non-current assets	57
Accounts payable	2,086	1,471
Accrued expenses and other current liabilities	(1,044)	1,334
Deferred revenue	(276)	1,475
Other liabilities, long-term	201
Net cash (used in) provided by operating activities	(1,822)	515
Investing activities
Acquisitions, net of cash acquired	(30,313)	0
Purchases of property and equipment and capitalized internal use software development cost	(3,196)	(687)
Purchase of short-term investments	(24,126)
Maturity of short-term investments	277
Increase of restricted cash		(250)
Net cash used in investing activities	(57,358)	(937)
Financing activities
Proceeds from follow-on offering, net of costs	52,184
Proceeds from exercise of stock options	780	1,569
Excess tax benefit related to stock options	82
Net cash used in investing activities	53,046	1,569
Effect of exchange rate fluctuations on cash and cash equivalents	(88)	(16)
Net change in cash and cash equivalents	(6,222)	1,131
Cash and cash equivalents at beginning of quarter	74,367	15,050
Cash and cash equivalents at end of quarter	68,145	16,181
Supplemental disclosure of other cash flow information:
Cash paid for income taxes	236	1
Supplemental disclosure of non-cash investing and financing activities:
Accretion of redeemable convertible preferred stock		13
Accrued stock offering costs	246	670
Issuance of stock for acquisition	$ 119,696