Facebook's decision to become a public company is seen as a bellwether for Web 2.0 stock offerings, but what will it mean for the social networking giant's 800 million users, and for the companies that build third-party apps for the site?

Facebook filed for its initial public offering (IPO) Wednesday afternoon, a move expected to raise it between US$5 billion and $10 billion. But it also means Facebook will come under greater public scrutiny, and it's likely to face intense pressure from investors to keep growing its business each quarter.

Industry analysts point to a few key areas where Facebook will seek to expand, through either in-house development or acquisitions. The changes could appear in what users are able to do on its site, and in how Facebook uses their data to make money.

Facebook will almost certainly improve the mobile experience for users. It has been explicit about its intention to "invest in new technologies so you have a great Facebook experience no matter where you go," as one company blog post put it.

Users can expect to see changes in the mobile experience sooner rather than later, said Brian Blau, a technology analyst at Gartner. "Facebook right now is a company that really has two experiences: desktop and mobile. Those experiences just in the past couple of months have started to look similar. You can see the direction Facebook is going."