Special thanks to Mike Arrington's TechCrunch (and thank you Mike for the link love, I am a huge fan of TechCrunch!) for alerting me that Facebook is expanding beyond high school and college facebooks. On August 31, 2005, I argued that if Facebook wanted to continue its remarkable growth, it ought to move into corporate social networks. You can read the post right here. It even drew comments from Matt Marshall at SiliconBeat.
Facebook appears to be following the same roll-out as it did with colleges. That is, start with the elite, then move down. Microsoft appears to be the first firm permitted to register. In this case, it was probably not a decision just of exclusivity, but considered the number of Facebook users who work at Microsoft. Couple that with Microsoft's tech-savvy workers being more likely to accept a corporate facebook, and you have a winning combination for a test company. It could not hurt that Bill Gates left Harvard early, just like Facebook founder & CEO Mark Zuckerberg. For testing purposes, companies like Goldman Sachs, McKinsey, Bain, BCG, Morgan Stanley and Blackstone would probably not look upon a corporate facebook as kindly as a tech company.
As of now, a search for "a" and "s" on Microsoft's facebook brings up 6 names and 12 names, respectively.
Facebook already "owns" the college market and can launch a job product to connect companies with their fresh crop of employees. If corporate facebook takes off like in colleges, Facebook could connect and "own" the job market. In that case, not only does LinkedIn become completely irrelevant, but HotJobs, Monster and the like will face a two front war: Craigslist on one side, "Mark's list"/Facebook Jobs on the other.
Update: Via InsideFacebook, the 10 companies and 1 not-for-profit that can access facebook.
Update II: Fred Stutzman summarizes the pros and cons of the corporate facebook.
Update III: Facebook dramatically expanded list of supported companies. You can find the list here.