Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
Operating activities
Net loss	$ (29,781)	$ (11,387)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense	4,335	1,410
Stock-based expense	15,933	3,255
Bad debt expense	783	847
Excess tax benefit related to stock-based compensation	(272)
Changes in operating assets and liabilities:
Accounts receivable	(4,800)	(5,506)
Prepaid expenses and other current assets	(228)	(1,077)
Other non-current assets	(116)	(213)
Accounts payable	3,176	2,227
Accrued expenses and other current liabilities	2,534	4,188
Deferred revenue	1,334	7,207
Other liabilities, long-term	1,138	263
Net cash provided by (used in) operating activities	(5,964)	1,214
Investing activities
Acquisitions, net of cash acquired	(30,314)
Purchases of property, equipment and capitalized internal-use software development costs, net	(5,830)	(2,820)
Purchases of short-term investments	(66,717)
Proceeds from sale of short-term investments	21,165
Increase in restricted cash		(250)
Net cash used in investing activities	(81,696)	(3,070)
Financing activities
Payments of initial stock offering costs		(937)
Proceeds from follow-on stock offering, net of costs	51,943
Proceeds from exercise of stock options	6,196	1,782
Excess tax benefit related to stock-based compensation	272
Net cash provided by financing activities	58,411	845
Effect of exchange rate fluctuations on cash and cash equivalents	(2)	(39)
Net decrease in cash and cash equivalents	(29,251)	(1,050)
Cash and cash equivalents at beginning of period	74,367	15,050
Cash and cash equivalents at end of period	45,116	14,000
Supplemental disclosure of other cash flow information:
Cash paid for income taxes	236	18
Supplemental disclosure of non-cash investing and financing activities:
Accretion of redeemable convertible preferred stock		25
Accrued stock offering costs		934
Issuance of stock for acquisition	$ 119,695