Condensed Consolidated Statements of Operations (unaudited) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Revenue:        
External customers $ 170,294 $ 151,952 $ 494,006 $ 431,317
Total revenue 170,294 151,952 494,006 431,317
Cost of services 34,782 33,988 118,410 103,470
Gross profit 135,512 117,964 375,596 327,847
Costs and expenses:        
Sales and marketing 68,416 62,850 240,492 209,470
Technology and development 20,379 19,396 61,509 52,928
General and administrative 21,882 120,984 73,700 160,815
Amortization of acquired intangible assets 1,982 2,084 8,344 6,251
Total costs and expenses 112,659 205,314 384,045 429,464
Income (loss) from operations 22,853 (87,350) (8,449) (101,617)
Other income (expense):        
Interest expense (111) (89) (403) (265)
Interest income 272 219 875 498
Other, net (85) 0 (214) (183)
Total other income 76 130 258 50
Income (loss) before income taxes 22,929 (87,220) (8,191) (101,567)
Income tax expense (benefit) 8,527 (22,075) (3,801) (27,784)
Net income (loss) $ 14,402 $ (65,145) $ (4,390) $ (73,783)
Net income (loss) per share attributable to common stockholders:        
Earnings per share, basic (in dollars per share) $ 0.16 $ (0.68) $ (0.05) $ (0.78)
Earnings per share, diluted (in dollars per share) $ 0.15 $ (0.68) $ (0.05) $ (0.78)
Weighted-average common shares outstanding used in computing net income (loss) per share attributable to common stockholders:        
Weighted average number of shares outstanding, basic (in shares) 92,034,474 95,340,136 93,052,376 94,659,931
Weighted average number of shares outstanding, diluted (in shares) 97,321,303 95,340,136 93,052,376 94,659,931
Consumer        
Revenue:        
External customers $ 161,671 $ 144,648 $ 470,260 $ 411,178
Costs and expenses:        
Income (loss) from operations 26,636 (84,249) 4,881 (90,456)
Enterprise        
Revenue:        
External customers 8,623 7,304 23,746 20,139
Costs and expenses:        
Income (loss) from operations $ (3,783) $ (3,101) $ (13,330) $ (11,161)