Facebook founder and CEO Mark Zuckerberg speaks during a news conference at Facebook headquarters on October 6, 2010 in Palo Alto, California.
Facebook filed for an IPO with the SEC late today. I've had a chance to review the S1 document, although I didn't really dig deeply into it. That can come later. The CliffNotes version is that there aren't any huge surprises here, as far as Facebook's financials go. There are over 800 million users. The business is all about advertising, the source of almost all of Facebook's revenue.
So what are the little surprises?
1. Facebook's future hinges on mobile. As plenty of folks have pointed out, pretty much everybody who is going to use Facebook already does — on a computer. This is where the money comes from: advertisers want to reach those people. On mobile devices, by contrast, Facebook doesn't do ads yet. There could be growth here. But mobile could also steal from Facebook's computer-bound business. From the S1: