The shares contained redemption features that were not solely within the Company's control. Accordingly, all shares of redeemable convertible preferred stock, were classified as temporary equity rather than as a component of stockholders' equity (deficit) in the Company's consolidated balance sheets for all periods prior to conversion.

The carrying value of redeemable convertible preferred stock was recorded at its fair value at the date of issue. In accordance with the standard, the Company accounted for changes in the redemption value over the period from the date of issuance to the earliest redemption date using the interest method to a value equal to the fair value, as determined by the Company using the most recent round of redeemable convertible preferred stock financing as an estimate for the fair value, of its redeemable convertible preferred stock over the period from the date of issuance to the earliest redemption date on June 14, 2016. As the Company did not have a round of redeemable preferred stock financing around December 31, 2009 or December 31, 2010, the Company determined the fair value by selecting a value that approximated an increase in value on a consistent basis between the Series D round (December 31, 2008) and the Series E round (June 14, 2011). The increases in the redemption value increases the value of the redeemable convertible preferred stock and decreases the additional paid-in capital and accumulated deficit balances.

In evaluating the fair value of preferred stock and the related preferred stock accretion leading up to the Company's initial public offering the Company considered the potential impact of the appreciation on the fair value of common stock between the June 14, 2011 Series E second closing as well as the convergence of the preferred stock and common stock prices as the likelihood of an initial public offering increased. The Company determined that following the filing of its registration statement on Form S-1 on July 29, 2011 a redemption was no longer probable given the decrease in the likelihood of a redemption occurring. Accordingly, effective July 29, 2011 the Company was no longer accreting its redeemable convertible preferred stock to its redemption value. Upon the completion of its initial public offering all mandatorily convertible preferred stock and related preferred stock accretion were reclassified to additional paid-in capital.