Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenues:
Research services	$ 47,341	$ 40,752	$ 91,888	$ 80,168
Advisory services and other	26,109	23,901	47,304	43,665
Total revenues	73,450	64,653	139,192	123,833
Operating expenses:
Cost of services and fulfillment	28,024	24,300	53,522	46,627
Selling and marketing	26,009	20,720	51,474	40,808
General and administrative	8,330	7,720	17,248	14,924
Depreciation	945	879	1,915	1,797
Amortization of intangible assets	526	905	1,219	1,810
Total operating expenses	63,834	54,524	125,378	105,966
Income from operations	9,616	10,129	13,814	17,867
Other income (expense), net	4	1,148	(105)	2,223
Gains on investments, net	58	27	640	452
Income before income taxes	9,678	11,304	14,349	20,542
Income tax provision	4,208	4,402	5,968	7,868
Net income	$ 5,470	$ 6,902	$ 8,381	$ 12,674
Basic income per common share	$ 0.24	$ 0.31	$ 0.37	$ 0.56
Diluted income per common share	$ 0.24	$ 0.30	$ 0.36	$ 0.55
Basic weighted average common shares outstanding	22,684	22,517	22,698	22,453
Diluted weighted average common shares outstanding	23,203	23,135	23,227	23,006