Condensed Consolidated Statements of Operations (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Revenue:    
Consumer revenue $ 128,201 $ 100,995
Enterprise revenue 6,207 6,591
Total revenue 134,408 107,586
Cost of services 34,556 29,957
Gross profit 99,852 77,629
Costs and expenses:    
Sales and marketing 77,079 56,539
Technology and development 16,866 12,729
General and administrative 18,955 13,335
Amortization of acquired intangible assets 2,084 2,231
Total costs and expenses 114,984 84,834
Loss from operations (15,132) (7,205)
Other income (expense):    
Interest expense (89) (87)
Interest income 117 60
Other (80) (11)
Total other expense (52) (38)
Loss before provision for income taxes (15,184) (7,243)
Income tax benefit (6,026) (2,948)
Net loss $ (9,158) $ (4,295)
Net loss per share    
Basic and diluted $ (0.10) $ (0.05)
Weighted-average common shares outstanding used in computing net loss per share:    
Basic and diluted 94,033,035 91,903,036