UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Agency revenues	$ 1,041,144	$ 769,928
Merchant revenues	526,998	528,564
Advertising and other revenues	73,660	3,520
Total revenues	1,641,802	1,302,012
Cost of revenues	235,331	292,347
Gross profit	1,406,471	1,009,665
Operating expenses:
Advertising — Online	520,848	403,153
Advertising — Offline	53,474	27,729
Sales and marketing	64,311	52,263
Personnel, including stock-based compensation of $38,803 and $21,709, respectively	194,531	134,218
General and administrative	72,981	50,161
Information technology	23,224	13,222
Depreciation and amortization	38,376	19,080
Total operating expenses	967,745	699,826
Operating income	438,726	309,839
Other income (expense):
Interest income	1,041	874
Interest expense	(17,745)	(17,329)
Foreign currency transactions and other	(5,969)	(2,942)
Total other income (expense)	(22,673)	(19,397)
Earnings before income taxes	416,053	290,442
Income tax expense	84,835	46,150
Net income	331,218	244,292
Less: net income attributable to noncontrolling interests	0	21
Net income applicable to common stockholders	$ 331,218	$ 244,271
Net income applicable to common stockholders per basic common share	$ 6.35	$ 4.89
Weighted average number of basic common shares outstanding	52,153	49,939
Net income applicable to common stockholders per diluted common share	$ 6.25	$ 4.76
Weighted average number of diluted common shares outstanding	53,018	51,353