Stockholders' Equity Note Disclosure [Text Block] | 10. Convertible Preferred Stock and Stockholders’ Equity Initial Public Offering On August 12, 2013, the Company closed its IPO in which it sold 5,125,000 shares of common stock at a public offering price of $9.00 per share. The aggregate offering price for shares sold in the offering was approximately $46.1 million. Net proceeds were approximately $40.0 million, after deducting underwriting discounts and commissions of $3.2 million and offering expenses of $2.9 million. Convertible Preferred Stock Upon the closing of the IPO on August 7, 2013, all outstanding shares of the Company’s convertible preferred stock automatically converted into 21,840,537 shares of common stock and the carrying value of $76.2 million is included in additional paid-in capital on the consolidated balance sheet as of December 31, 2015 and 2014. Immediately following the closing of the IPO, the Company’s certificate of incorporation was amended to authorize 20,000,000 shares of undesignated preferred stock and 200,000,000 shares of common stock. Preferred Stock In association with the IPO, the board of directors authorized the Company to issue up to 20,000,000 shares of preferred stock, par value $0.001 per share. As of December 31, 2015 and 2014, no shares of preferred stock were outstanding. Common Stock At December 31, 2015 and 2014 there were 34,455,220 and 33,066,327 shares of common stock issued and outstanding, respectively. The following table summarizes common stock activity during the year ended December 31, 2015: Number of Shares Outstanding at December 31, 2014 33,066,327 Option and warrant exercises 268,172 RSUs vesting 723,978 Common stock issued in connection with employee stock purchase plan 396,743 Outstanding at December 31, 2015 34,455,220 Treasury Stock The Company has 66,666 shares of treasury stock related to the acquisition of Crowd Science. Treasury stock is carried at cost and could be re-issued if the Company determined to do so. Equity Incentive Plans The Company’s 2004 Stock Plan (the “2004 Plan”) authorized the Company to grant restricted stock awards or stock options to employees, directors and consultants at prices not less than the fair market value at date of grant for incentive stock options and not less than 85% of fair market value for non-statutory options. Option vesting schedules were determined by the board of directors at the time of issuance and they generally vest at 25% on the first anniversary of the grant (or the employment or service commencement date) and monthly over the next 36 months. Options generally expire ten years from the date of grant unless the optionee is a 10% stockholder, in which case the term will be five years from the date of grant. Unvested options exercised are subject to the Company’s repurchase right. Upon the effective date of the registration statement related to the Company’s IPO, the 2004 Plan was amended to cease the grant of any additional awards thereunder, although the Company will continue to issue common stock upon the exercise of stock options previously granted under the 2004 Plan . In July 2013, the Company adopted a 2013 Equity Incentive Plan (the “2013 Plan”) which became effective on August 6, 2013. The 2013 Plan serves as the successor equity compensation plan to the 2004 Plan. The 2013 Plan will terminate on July 23, 2023. The 2013 Plan provides for the grant of incentive stock options, nonqualified stock options, restricted stock awards, stock appreciation rights, performance stock awards, restricted stock units and stock bonus awards to employees, directors and consultants. Stock options granted must be at prices not less than 100% of the fair market value at date of grant. Option vesting schedules are determined by the Company at the time of issuance and they generally vest at 25% on the first anniversary of the grant (or the employment or service commencement date) and monthly over the next 36 months. Options generally expire ten years from the date of grant unless the optionee is a 10% stockholder, in which case the term will be five years from the date of grant. Unvested options exercised are subject to the Company’s repurchase right. The Company initially reserved 2,000,000 shares of its common stock for issuance under the 2013 Plan, and shares reserved for issuance increase January 1 of each year by the lesser of (i) 5% of the number of shares issued and outstanding on December 31 immediately prior to the date of increase or (ii) such number of shares as may be determined by the board of directors. Prior to the IPO, the fair value of the common stock underlying the Company’s stock options was determined by the Company’s board of directors, which intended all options granted to be exercisable at a price per share not less than the per-share fair value of the Company’s common stock underlying those options on the date of grant. The valuations of the Company’s common stock were determined in accordance with the guidelines outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. The assumptions the Company used in the valuation model are based on future expectations combined with management judgment. In the absence of a public trading market, the Company’s board of directors, with input from management, exercised significant judgment and considered numerous objective and subjective factors to determine the fair value of the Company’s common stock as of the date of each option grant. Subsequent to the IPO, the fair value of the common stock underlying the Company’s stock options is the closing price of the Company’s stock as of the grant date. The following table summarizes option activity: Number of Shares (in thousands) Weighted- A verage Exercise Price Weighted- Average Remaining Contractual Life (years) Aggregate Intrinsic Value ( 1 ) (in thousands) Balance at December 31, 2012 4,015 $ 3.78 7.88 $ 8,659 Granted 2,069 $ 8.58 Exercised (192 ) $ 1.99 Canceled and forfeited (179 ) $ 5.44 Balance at December 31, 2013 5,713 $ 5.53 7.31 $ 13,704 Granted 783 $ 5.44 Exercised (802 ) $ 3.79 Canceled and forfeited (635 ) $ 7.47 Balance at December 31, 2014 5,059 $ 5.54 5.78 $ 3,461 Granted (2) 1,034 $ 5.17 Exercised (256 ) $ 3.09 Canceled and forfeited (3) (1,477 ) $ 7.18 Balance at December 31, 2015 4,360 $ 5.04 6.30 $ 1,480 Vested as of December 31, 2015 and expected to vest thereafter (4) 4,212 $ 5.00 6.23 $ 1,476 Vested and exercisable as of December 31, 2015 3,142 $ 4.59 5.63 $ 1,458 (1) The aggregate intrinsic value represents the difference between the Company’s estimated fair value of its common stock and the exercise price of outstanding in-the-money options as of those dates. (2) Options granted include 0.7 million re-issued options in connection with a modification. See “Modification of Employee Stock Options” below for more information. (3) Options cancelled and forfeited include 0.7 million options that were cancelled in connection with a modification. See “ Modification of Employee Stock Options below for more information. (4) Options expected to vest reflect an estimated forfeiture rate. The weighted average grant date fair value of options granted was $2.78, $3.76 and $5.89 in 2015, 2014 and 2013, respectively. Prior to the Company’s IPO, aggregate intrinsic value represented the difference between the Company’s estimated fair value of its common stock and the exercise price of outstanding, in-the-money options. After the Company’s IPO, aggregate intrinsic value represents the difference between the market value of the Company’s common stock and the exercise price of outstanding, in-the-money options. The total intrinsic value of options exercised was approximately $0.5 million, $2.0 million and $1.3 million for 2015, 2014 and 2013, respectively. The following table summarizes restricted stock unit activity: Number of Shares (in thousands) Weighted A verage Fair Value at Grant Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value (1) (in thousands) Balance at December 31, 2012 — $ — — $ — Granted 42 $ 8.21 Released (4 ) $ 8.89 Balance at December 31, 2013 38 $ 8.15 2.13 $ 284 Granted 1,202 $ 5.89 Released (15 ) $ 7.92 Canceled and forfeited (142 ) $ 6.05 Balance at December 31, 2014 1,083 $ 5.92 1.39 $ 5,458 Granted 1,660 $ 5.36 Released (738 ) $ 5.82 Canceled and forfeited (386 ) $ 5.90 Balance at December 31, 2015 1,619 $ 5.39 0.99 $ 5,681 (1) The intrinsic value of RSUs is based on the Company’s closing stock price as reported by the New York Stock Exchange on December 31, 2013, 2014 and 2015. The Company did not grant any RSUs prior to 2013. The total grant date fair value of restricted stock units vested during the years ended December 31, 2015 and 2014 was $4.3 million and $0.1 million, respectively. All of our RSUs that were released during the years ended December 31, 2015, 2014 and 2013 were net share settled. As such, upon each release date, RSUs were withheld to cover the required withholding tax, which is based on the value of the RSU on the release date as determined by the closing price of our common stock on the trading day of the settlement date. The remaining amounts are delivered to the recipient as shares of our common stock. Modification of Employee Stock Options On January 2, 2015, the Company modified options to purchase 0.7 million shares of common stock previously granted to non-executive employees with exercise prices over $7.00 per share. The exercise price of the modified options was reduced to $5.14 per share, the closing price of the Company’s common stock on the New York Stock Exchange on January 2, 2015. No other terms of these options were modified. The Company expects to recognize an additional $0.4 million of stock-based compensation expense over the remaining vesting terms of the options as a result of the modification. Employee Stock Purchase Plan In July 2013, the Company adopted a 2013 Employee Stock Purchase Plan (the “2013 Purchase Plan”) that became effective on August 6, 2013. The 2013 Purchase Plan is designed to enable eligible employees to periodically purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation, subject to any plan limitations. At the end of each offering period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the last day of the offering period . Purchases are accomplished through participation in discrete offering periods. The 2013 Purchase Plan is intended to qualify as an employee stock purchase plan under Section 423 of the Internal Revenue Code. The Company initially reserved 500,000 shares of its common stock for issuance under the 2013 Purchase Plan and shares reserved for issuance increase January 1 of each year by the lesser of (i) a number of shares equal to 1% of the total number of outstanding shares of common stock on December 31 immediately prior to the date of increase or (ii) such number of shares as may be determined by the board of directors. The expected term of ESPP shares is the average of the remaining purchase periods under each offering period. The assumptions used to value employee stock purchase rights were as follows: Year Ended December 31, 2015 Year Ended December 31, 2014 Year Ended December 31, 2013 Expected term (years) 0.50 0.50 0.47 Volatility 56% 80% 80% Risk-free interest rate 0.07% - 0.36% 0.05% - 0.08% 0.08% Dividend yield — — — Shares Reserved for Future Issuance At December 31, 2015 and 2014, the Company has reserved the following shares of common stock for future issuance: December 31, 201 5 201 4 Common stock reserved: Common stock options 4,360,015 5,058,641 Restricted stock units 1,618,543 1,082,939 Warrants to purchase common stock — 24,838 Shares available for future issuance under the 2013 Plan 3,680,862 984,455 Employee stock purchase plan 437,934 504,014 10,097,354 7,654,887 Stock-Based Compensation The fair value of options granted to employees is estimated on the grant date using the Black-Scholes option valuation model. This valuation model for stock-based compensation expense requires the Company to make assumptions and judgments about the variables used in the calculation including the expected term (weighted-average period of time that the options granted are expected to be outstanding), volatility of the Company’s common stock, a risk-free interest rate, expected dividends, and the estimated forfeitures of unvested stock options. To the extent actual results differ from the estimates, the difference will be recorded as a cumulative adjustment in the period estimates are revised. The Company uses the simplified calculation of expected life, and volatility is based on an average of the historical volatilities of the common stock of a group of entities with characteristics similar to those of the Company. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the option. Expected forfeitures are based on the Company’s historical experience. The Company currently has no history or expectation of paying cash dividends on common stock. The fair value of options granted to employees is determined using the Black-Scholes option valuation model with the following assumptions: Years Ended December 31, 201 5 201 4 2013 Expected term (years) 6.00 6.00 5.51 - 6.12 Volatility 56% - 80% 80% 80% Risk-free interest rate 1.54% - 1.79% 1.74% - 2.02% 1.06% - 1.72% Dividend yield — — Weighted-average fair value $2.78 $3.76 $5.89 The following table summarizes the effects of stock-based compensation related to vesting stock-based awards included in the consolidated statements of operations (in thousands): Years Ended December 31, 201 5 201 4 201 3 Cost of revenue $ 312 $ 342 $ 185 Sales and marketing 3,403 2,776 1,806 Research and development (1) 1,111 482 346 General and administrative 4,053 2,174 1,497 Total stock-based compensation $ 8,879 $ 5,774 $ 3,834 (1) Excludes $544,000, $360,000 and $226,000 of stock-based compensation expense that was capitalized as part of internal-use software development costs for the years ended December 31, 2015, 2014 and 2013, respectively. No income tax benefit has been recognized relating to stock-based compensation expense and no tax benefits have been realized from exercised stock options during the years ended December 31, 2015, 2014 and 2013. As of December 31, 2015, there was $9.9 million of unrecognized compensation cost, adjusted for estimated forfeitures, related to non-vested stock-based awards which will be recognized over a weighted average period of 1.81 years. Total unrecognized compensation cost will be adjusted for future changes in estimated forfeitures. Warrants In conjunction with a lease agreement, the Company issued warrants to purchase 24,838 shares of Series A-2 preferred stock on December 31, 2006. These warrants had an exercise price of $1.2078 per share. On August 12, 2013, upon the closing of the Company’s IPO, the warrants were converted from warrants to purchase preferred stock to warrants to purchase common stock and the liability at their then fair value of $0.4 million was reclassified to additional paid-in capital. Prior to the conversion of the warrant liability on August 12, 2013, the Company’s preferred stock warrants were recorded at fair value. Changes in the fair value of the warrants were recorded in “Other income (expense), net” in the consolidated statements of operations. The fair value of the warrants which, prior to the closing of the Company’s IPO on August 12, 2013, were recorded as liabilities on the consolidated balance sheets and which were remeasured to fair value on a recurring basis at each balance sheet date, were determined using the Black-Scholes option pricing model with the following assumptions: Year 2013 through August 12 Expected term (years) 3.41 - 5.76 Volatility 80% Risk-free interest rate 0.47% - 1.77% Dividend yield — A summary of the fair value of the warrants outstanding immediately prior to the closing of the Company’s IPO on August 12, 2013 are shown in the table below (in thousands): August 12 , 201 3 Warrant (series A-2) $ 203 Warrant (series C) 223 Total fair value $ 426 The change in total fair value of the convertible preferred stock warrants has been recorded as a component of “Other income (expense)” in the consolidated statements of operations. After the warrants were converted into warrants for common stock in association with the completion of the Company’s IPO in August 2013, the total fair value of the warrants is no longer subject to remeasurement. As of December 31, 2015, no warrants to purchase common stock were outstanding. |