With estimated revenues of $150 million, Facebook would normally be valued at between one times its revenue to perhaps 10 times revenues, if it was growing like crazy. With a valuation of $15 billion, this would be 100 times revenues. If you owned a company with total revenues of $50,000, then Microsoft Corporation (MSFT: would value your business at $5 million.

Facebook's already grown like crazy and perhaps has a few more years to go, but it can't get too much bigger.

Microsoft is going to place ads, sell ads, broker ads and do some sort of revenue split with Facebook. For that, Microsoft pays $240 million and gets 1.6% of the company. When you extrapolate the valuation of Facebook and run the figures against the user base of around 50 million, it means that each and every user is tallied at $300 a head.

I thought valuing registered users of Web sites got expensive back in 1999, when they were as high as $100 a head; $300 is sky-high.

But this is $300 a head for what are essentially bloggers, duds, poor students and hangers-on. What are these people constantly buying that makes them worth that much?

Labels: facebook, john c dvorak, msft, online ads, venture