Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 71,662	$ 13,855
Short-term investments	0	10,000
Accounts receivable (net of reserves of $13 and $17 at September 30, 2011 and December 31, 2010 , respectively)	868	644
Prepaid expenses and other current assets	1,770	551
Total current assets	74,300	25,050
Property and equipment, net	19,825	15,818
Other assets	227	73
Acquired intangible assets, net	1,121	0
Goodwill	1,514	0
Total assets	96,987	40,941
Current liabilities:
Accounts payable	1,841	4,868
Accrued expenses	7,730	3,947
Current portion of deferred revenue	38,421	28,616
Total current liabilities	47,992	37,431
Deferred revenue, net of current portion	15,433	10,106
Other long-term liabilities	295	297
Commitments and contingencies (Note 9)
Stockholders' equity (deficit):
Preferred stock, $0.01 par value; 6,000,000 and 0 shares authorized and outstanding at September 30, 2011 and December 31, 2010
Common stock, $0.01 par value; 45,000,000 and 21,539,370 shares authorized at September 30, 2011 and December 31, 2010, respectively; 25,094,045 and 4,526,603 shares outstanding at September 30, 2011 and December 31, 2010, respectively	251	45
Additional paid-in capital	127,339	2,134
Accumulated deficit	(94,306)	(77,805)
Treasury stock, at cost (2,009 shares at September 30, 2011)	(22)	0
Accumulated other comprehensive income	5	3
Total stockholders' equity (deficit)	33,267	(75,623)
Total liabilities, convertible and redeemable convertible preferred stock, and stockholders' equity (deficit)	96,987	40,941
Redeemable Convertible Preferred Stock [Member]
Redeemable and convertible preferred stock:
Redeemable convertible preferred stock	0	4,404
Convertible Preferred Stock [Member]
Redeemable and convertible preferred stock:
Redeemable convertible preferred stock	$ 0	$ 64,326