Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 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 six months ended June 30, 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	(753,972	)	753,972		88.81
Exercised	—		(135,651	)	12.88
Canceled	48		(48	)	35.95
Expired	(1,160,721	)	—		—
Balances as of June 30, 2012	5,098,863		3,576,027		73.31		6.76	$	76,199
Vested and exercisable at June 30, 2012			3,576,027		73.31		6.76	$	76,199

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				Six Months Ended
	June 30, 2012		June 30, 2011		June 30, 2012		June 30, 2011
Dividend yield	—	%	—	%	—	%	—	%
Expected volatility	61	%	51	%	61% - 65%		51% - 52%
Risk-free interest rate	2.01	%	3.35	%	1.97% - 2.01%		3.35% - 3.42%
Suboptimal exercise factor	2.26 - 3.65		2.22 – 3.54		2.26 - 3.65		2.17 – 3.54

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						Six Months Ended
	June 30, 2012			June 30, 2011			June 30, 2012			June 30, 2011
	(in thousands)
Fulfillment expenses	$	90		$	679		$	157		$	1,240
Marketing	817			1,485			2,221			2,734
Technology and development	10,440			7,005			21,040			12,297
General and administrative	7,103			6,367			14,364			11,529
Stock-based compensation expense before income taxes	18,450			15,536			37,782			27,800
Income tax benefit	(7,120		)	(5,973		)	(14,580		)	(10,720		)
Stock-based compensation after income taxes	$	11,330		$	9,563		$	23,202		$	17,080