How Many Users Does Second Life Really Have?

It is another of the Internet's most cutting-edge applications outside the Web: the online community of surrogate identities in the 3D realm of Second Life. It's a virtual world supported by real dollars from companies that lease virtual space, providing the service with real revenue. But just how many real users does it have?

In a recent partnership agreement announced with the National Basketball Association, Commissioner David Stern cited what he characterized as Second Life's six million users. A check today of the site's Web home page refer to its 6.16 million "residents," 1.62 million of whom have logged on within the past 60 days.

In a story for InformationWeek published last week, Executive Editor Mitch Wagner asked a representative of Linden Lab for a clarification of Stern's quote. As he describes in a blog post last Friday, the number he received in return was staggering: While the company estimates its own flesh-and-blood user base to have reached 3.2 million at the end of last March, he learned, its actual user retention rate is close to 10%. Based on that formula, Linden Lab's everyday user count is close to 320,000.