Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 97,196	$ 29,956
Accounts receivable, net	133,267	94,722
Prepaid expenses and other current assets	7,514	4,141
TOTAL CURRENT ASSETS	237,977	128,819
Property and equipment, net	15,196	8,712
Internal use software development costs, net	11,501	7,204
Goodwill	16,290	1,491
Intangible assets, net	14,090	510
Other assets, non-current	1,427	3,151
TOTAL ASSETS	296,481	149,887
Current liabilities:
Accounts payable and accrued expenses	151,021	120,198
Debt and capital lease obligations, current portion	105	288
Other current liabilities	3,276	2,901
TOTAL CURRENT LIABILITIES	154,402	123,387
Debt and capital leases, net of current portion	0	3,893
Convertible preferred stock warrant liabilities	0	5,451
Other liabilities, non-current	1,879	996
Contingent consideration liability	11,448	0
TOTAL LIABILITIES	167,729	133,727
Commitments and contingencies (Note 16)
Series A, B, C, and D convertible preferred stock, $0.00001 par value, 29,691 shares authorized at December 31, 2013; 28,820 shares issued and outstanding at December 31, 2013	0	52,571
STOCKHOLDERS’ EQUITY (DEFICIT)
Preferred stock, $0.00001 par value, 10,000 shares authorized at December 31, 2014; 0 shares issued and outstanding at December 31, 2014	0	0
Common stock, $0.00001 par value; 500,000 and 73,380 shares authorized at December 31, 2014 and December 31, 2013, respectively; 37,192 and 11,855 shares issued and outstanding at December 31, 2014 and December 31, 2013, respectively	0	0
Additional paid-in capital	209,472	25,532
Accumulated other comprehensive (loss) income	(8)	96
Accumulated deficit	(80,712)	(62,039)
TOTAL STOCKHOLDERS’ EQUITY (DEFICIT)	128,752	(36,411)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT)	$ 296,481	$ 149,887