UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Agency revenues	$ 1,118,128	$ 876,601	$ 2,427,751	$ 1,797,204
Merchant revenues	584,969	573,230	1,632,402	1,558,564
Other revenues	3,213	2,973	10,163	9,071
Total revenues	1,706,310	1,452,804	4,070,316	3,364,839
Cost of revenues	309,809	352,656	926,385	1,009,657
Gross profit	1,396,501	1,100,148	3,143,931	2,355,182
Operating expenses:
Advertising - Online	375,204	279,926	966,820	701,317
Advertising - Offline	8,441	8,035	29,519	29,463
Sales and marketing	52,961	47,124	145,943	122,931
Personnel, including stock-based compensation of $17,555, $13,298, $51,690, and $40,404, respectively	135,210	94,463	343,916	255,450
General and administrative	42,287	31,717	122,768	87,334
Information technology	10,799	8,548	31,974	23,456
Depreciation and amortization	16,007	13,957	47,513	40,087
Total operating expenses	640,909	483,770	1,688,453	1,260,038
Operating income	755,592	616,378	1,455,478	1,095,144
Other income (expense):
Interest income	905	2,526	3,004	6,075
Interest expense	(17,067)	(7,879)	(45,208)	(23,389)
Foreign currency transactions and other	(8,256)	827	(7,427)	(8,696)
Total other income (expense)	(24,418)	(4,526)	(49,631)	(26,010)
Earnings before income taxes	731,174	611,852	1,405,847	1,069,134
Income tax expense	(131,201)	(138,966)	(271,405)	(235,959)
Net income	599,973	472,886	1,134,442	833,175
Less: net income attributable to noncontrolling interests	3,387	3,387	3,539	2,520
Net income applicable to common stockholders	$ 596,586	$ 469,499	$ 1,130,903	$ 830,655
Net income applicable to common stockholders per basic common share (in dollars per share)	$ 11.97	$ 9.43	$ 22.70	$ 16.74
Weighted average number of basic common shares outstanding (in shares)	49,851	49,779	49,830	49,607
Net income applicable to common stockholders per diluted common share (in dollars per share)	$ 11.66	$ 9.17	$ 22.05	$ 16.23
Weighted average number of diluted common shares outstanding (in shares)	51,185	51,184	51,295	51,193