Convertible preferred stock	12 Months Ended
Dec. 31, 2013
Convertible preferred stock
Convertible preferred stock	9. Convertible preferred stock The preferred stock consists of 2,243,750 shares designated (and issued) as Series A Preferred Stock, and 1,756,250 shares which are undesignated (and unissued). Each issued share of Series A Preferred Stock is convertible into approximately 3.05 shares of common stock, for a total of 6,851,144 shares of common stock. Series A Preferred Stock may be converted into shares of common stock at any time at the election of the holder. In addition, all issued Series A Preferred Stock automatically convert into shares of common stock upon the consent of the holders of at least two-thirds of the voting power of the issued Series A Preferred Stock, or immediately prior to the closing of an initial public offering of common stock registered with the U.S. Securities and Exchange Commission in which the valuation of the Company is at least $50.0 million and the net proceeds of the offering are at least $25.0 million. Upon the admission of the Company's common stock to AIM in March 2006, substantially all of the rights, preferences and privileges of the Series A preferred stockholders, except for the liquidation preference, terminated. The only difference in rights between the Series A Preferred Stock and the common stock is the payment of a liquidation preference on the Series A Preferred Stock in the event of an acquisition, liquidation or winding up of the Company. "Acquisition" is defined for purposes of payment of the liquidation preference as a consolidation or merger (or similar transaction) of the Company with or into any other corporation or the sale of all of the capital stock of the Company, in each case where the shareholders immediately prior to such transaction fail to retain a majority voting power of the Company's stock following such transaction, or a sale, lease, exclusive license or other disposition of all or substantially all of the Company's assets. Upon such a liquidation event, each share of Series A Preferred Stock entitles its holder to receive an amount equal to the original purchase price for the Series A Preferred Stock prior to payment on the common stock. The aggregate liquidation preference for the Series A Preferred Stock is approximately $9.0 million. In the event of an acquisition of the Company, the holders of Series A Preferred Stock would be entitled to receive the first approximately $9.0 million of the purchase price. After payment of this liquidation preference, the remaining proceeds would be distributed pro rata among the holders of common stock. The Series A Preferred Stock otherwise has identical rights to common stock on an as converted basis, including with respect to voting and dividends.

9. Convertible preferred stock

The preferred stock consists of 2,243,750 shares designated (and issued) as Series A Preferred Stock, and 1,756,250 shares which are undesignated (and unissued). Each issued share of Series A Preferred Stock is convertible into approximately 3.05 shares of common stock, for a total of 6,851,144 shares of common stock. Series A Preferred Stock may be converted into shares of common stock at any time at the election of the holder. In addition, all issued Series A Preferred Stock automatically convert into shares of common stock upon the consent of the holders of at least two-thirds of the voting power of the issued Series A Preferred Stock, or immediately prior to the closing of an initial public offering of common stock registered with the U.S. Securities and Exchange Commission in which the valuation of the Company is at least $50.0 million and the net proceeds of the offering are at least $25.0 million.

Upon the admission of the Company's common stock to AIM in March 2006, substantially all of the rights, preferences and privileges of the Series A preferred stockholders, except for the liquidation preference, terminated. The only difference in rights between the Series A Preferred Stock and the common stock is the payment of a liquidation preference on the Series A Preferred Stock in the event of an acquisition, liquidation or winding up of the Company. "Acquisition" is defined for purposes of payment of the liquidation preference as a consolidation or merger (or similar transaction) of the Company with or into any other corporation or the sale of all of the capital stock of the Company, in each case where the shareholders immediately prior to such transaction fail to retain a majority voting power of the Company's stock following such transaction, or a sale, lease, exclusive license or other disposition of all or substantially all of the Company's assets. Upon such a liquidation event, each share of Series A Preferred Stock entitles its holder to receive an amount equal to the original purchase price for the Series A Preferred Stock prior to payment on the common stock. The aggregate liquidation preference for the Series A Preferred Stock is approximately $9.0 million. In the event of an acquisition of the Company, the holders of Series A Preferred Stock would be entitled to receive the first approximately $9.0 million of the purchase price. After payment of this liquidation preference, the remaining proceeds would be distributed pro rata among the holders of common stock. The Series A Preferred Stock otherwise has identical rights to common stock on an as converted basis, including with respect to voting and dividends.