2. Net Income (Loss) Per Share

Prior to the Company's IPO, net income per share was computed as required by provisions within the accounting standard for earnings per share, which established guidance regarding the computation of earnings per share, or EPS, by companies that have issued securities other than common stock that contractually entitle the holder to participate in dividends and earnings of the Company. The accounting standard for earnings per share requires earnings for the period, after deduction of preferred stock dividends, to be allocated between the common and preferred stockholders based on their respective rights to receive dividends, whether or not declared. Basic net income per share is then calculated by dividing income attributable to common stockholders (after the reduction for any preferred stock dividends assuming current income for the period had been distributed) by the weighted-average number of shares of common stock outstanding for the period, net of shares subject to repurchase by the Company. The accounting standard for earnings per share does not require the presentation of basic and diluted net income per share for securities other than common stock; therefore, the following net income (loss) per share amounts only pertain to the Company's common stock. The Company calculated diluted net income per share under the as-if-converted method unless the conversion of the preferred stock was anti-dilutive to basic net income per share. To the extent preferred stock was anti-dilutive, the Company calculated diluted net income per share under the two-class method.

Subsequent to the Company's IPO, net income per share continued to be computed as required by provisions within the accounting standard for earnings per share. Basic EPS is calculated by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted EPS is computed by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding for the period and the weighted-average number of dilutive common stock equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, common stock options and restricted stock units are considered to be common stock equivalents and are only included in the calculation of diluted EPS when their effect is dilutive.

Subsequent to its IPO, the Company has two classes of stock outstanding, Class A common stock and Class B common stock. The economic rights of the Class A common stock and Class B common stock, including rights in connection with dividends and payments upon a liquidation or merger are identical, and the Class A common stock and Class B common stock will be treated equally, identically and ratably, unless differential treatment is approved by the Class A common stock and Class B common stock, each voting separately as a class. The Company computes basic earnings per share by dividing net income attributable to common stockholders by the weighted average number of shares of Class A and Class B common stock outstanding during the period. For diluted earnings per share, the Company divides net income attributable to common stockholders by the sum of the weighted average number of shares of Class A and Class B common stock outstanding and the potential number of shares of dilutive Class A and Class B common stock outstanding during the period.

The Company excluded 5,778 and 4,288 common stock equivalents resulting from outstanding equity awards for the three and nine months ended September 30, 2011, respectively, from the calculation of diluted net income (loss) per share due to their anti-dilutive nature. The Company excluded 842 and 728 common stock equivalents resulting from outstanding equity awards for the three and nine months ended September 30, 2010, respectively, from the calculation of diluted net income (loss) per share due to their anti-dilutive nature.