Some stats from May 2005:
- Out of 1400 universities in the US, 640 have been launched.
- In those universities, they have a 50 to 90 percent penetration
- Total number of registered users: 2.6 million
- Frequency of visits: 65% of the user base visits the site every day, 95% every month
- Average number of visits per day: 6
- Traffic: 3 billion page views from US registered users
I remember logging in to Facebook using an account from a Dutchman studying in the US at that time. We were planning a project together and he was totally excited about Facebook (and its lean design in particular).