How Much Is a User Worth?

Internet companies are notoriously difficult to value, as investors learned in the dot-com crash 11 years ago. But since the "Web 2.0" companies fueling this year's Internet IPOs rely upon having a reliable group of engaged users, they do offer at least one telling metric: the amount of money each user is worth. That's why venture capitalists evaluating such businesses in their early stages often examine how much revenue a company is generating per user. Bijan Sabet, a venture capitalist at Spark Capital, which has invested in several Internet companies, including Twitter, FourSquare, and Tumblr, says his firm often considers $2 of annual revenue per user to be an important target threshold for startups. By that measure, several of today's new Web companies show genuine promise.