| Schedule of Quarterly Financial Information |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended | | | Mar. 31, 2013 | | Jun. 30, 2013 | | Sep. 30, 2013 | | Dec. 31, 2013 | | Mar. 31, 2014 | | Jun. 30, 2014 | | Sep. 30, 2014 | | Dec. 31, 2014 | | | (unaudited) | | | (in thousands, except per share data) | Revenues | | $ | 24,883 |
| | $ | 26,291 |
| | $ | 27,749 |
| | $ | 29,039 |
| | $ | 30,356 |
| | $ | 32,302 |
| | $ | 34,348 |
| | $ | 36,573 |
| Cost of revenues | | 5,795 |
| | 5,924 |
| | 6,415 |
| | 6,526 |
| | 6,846 |
| | 7,175 |
| | 7,421 |
| | 7,521 |
| Gross profit | | 19,088 |
| | 20,367 |
| | 21,334 |
| | 22,513 |
| | 23,510 |
| | 25,127 |
| | 26,927 |
| | 29,052 |
| Operating expenses: | | | | | | | | | | | | | | | | | Research and development | | 5,297 |
| | 5,291 |
| | 5,151 |
| | 5,939 |
| | 6,404 |
| | 6,411 |
| | 6,490 |
| | 7,015 |
| Sales and marketing | | 10,168 |
| | 10,160 |
| | 10,411 |
| | 11,784 |
| | 12,492 |
| | 11,845 |
| | 11,774 |
| | 11,938 |
| General and administrative | | 3,896 |
| | 4,053 |
| | 4,277 |
| | 4,566 |
| | 4,875 |
| | 5,081 |
| | 5,156 |
| | 5,888 |
| Total operating expenses | | 19,361 |
| | 19,504 |
| | 19,839 |
| | 22,289 |
| | 23,771 |
| | 23,337 |
| | 23,420 |
| | 24,841 |
| Income (loss) from operations | | (273 | ) | | 863 |
| | 1,495 |
| | 224 |
| | (261 | ) | | 1,790 |
| | 3,507 |
| | 4,211 |
| Other income (expense), net(2) | | (270 | ) | | 51 |
| | 12 |
| | (61 | ) | | 12 |
| | 41 |
| | (119 | ) | | (568 | ) | Income (loss) before income taxes (2) | | (543 | ) | | 914 |
| | 1,507 |
| | 163 |
| | (249 | ) | | 1,831 |
| | 3,388 |
| | 3,643 |
| Provision for (benefit from) income taxes(1) | | 70 |
| | 92 |
| | 210 |
| | 128 |
| | 182 |
| | 174 |
| | 283 |
| | (22,270 | ) | Net income (loss) (2) | | $ | (613 | ) | | $ | 822 |
| | $ | 1,297 |
| | $ | 35 |
| | $ | (431 | ) | | $ | 1,657 |
| | $ | 3,105 |
| | $ | 25,913 |
| Net income (loss) attributable to common stockholders | | $ | (613 | ) | | $ | 821 |
| | $ | 1,295 |
| | $ | 35 |
| | $ | (431 | ) | | $ | 1,657 |
| | $ | 3,105 |
| | $ | 25,913 |
| Net income (loss) per share attributable to common stockholders: | | | | | | | | | | | | | | | | | Basic (2) | | $ | (0.02 | ) | | $ | 0.03 |
| | $ | 0.04 |
| | $ | 0.00 |
| | $ | (0.01 | ) | | $ | 0.05 |
| | $ | 0.09 |
| | $ | 0.77 |
| Diluted (2) | | $ | (0.02 | ) | | $ | 0.02 |
| | $ | 0.04 |
| | $ | 0.00 |
| | $ | (0.01 | ) | | $ | 0.04 |
| | $ | 0.08 |
| | $ | 0.69 |
|
(1) Provision for income taxes consists primarily of taxes on income in foreign jurisdictions and state income taxes in the U.S. In the fourth quarter of 2014, the Company recorded a tax benefit of $23.7 million to recognize its U.S. federal and certain state deferred tax assets. (2) Other income (expense), income (loss) before income taxes, net income (loss), net income (loss) attributable to common stockholders and net income (loss) per share have been adjusted for an immaterial error as further described in Note 1 to the consolidated financial statements. |