Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2012

Stockholders' Equity Note [Abstract]

Summary Of Activity Related To Stock Option Plans

A summary of the activity related to the Company’s stock option plans during the three months ended March 31, 2012 is as follows:

			Options Outstanding
	Shares Available for Grant		Number of Shares		Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (in Thousands)
Balances as of December 31, 2011	7,013,508		2,957,754		$	66.59
Granted	(347,367	)	347,367		97.75
Exercised	—		(117,016	)	10.47
Canceled	48		(48	)	35.95
Expired	(1,160,721	)	—		—
Balances as of March 31, 2012	5,505,468		3,188,057		72.04		6.61	$	183,361
Vested and exercisable at March 31, 2012			3,188,057		72.04		6.61	$	183,361

Summary Of Assumptions Used To Value Stock Option Grants Using Lattice-Binomial Model

The following table summarizes the assumptions used to value stock option grants using the lattice-binomial model:

	Three Months Ended
	March 31, 2012		March 31, 2011
Dividend yield	—	%	—	%
Expected volatility	65	%	52	%
Risk-free interest rate	1.97	%	3.42	%
Suboptimal exercise factor	2.26 - 3.65		2.17 – 3.39

Summary Of Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense, net of tax, related to stock option plans which was allocated as follows:

	Three Months Ended
	March 31, 2012			March 31, 2011
	(in thousands)
Fulfillment expenses	$	67		$	560
Marketing	1,404			1,249
Technology and development	10,600			5,292
General and administrative	7,261			5,163
Stock-based compensation expense before income taxes	19,332			12,264
Income tax benefit	(6,708		)	(4,744		)
Stock-based compensation after income taxes	$	12,624		$	7,520