One thing to realize about Facebook is that it is a platform. A platform allows developers and companies to build on top of it, build apps for it and interact with it through a variety of mediums. In that way, Apple’s iOS and Google’s Android are both platforms, but Android and iOS are also operating systems – complex sets of software that connect hardware to the platform. Facebook is a fine platform, but it is not an operating system. And that is going to make the company’s attempt at building a “Facebook Phone” extremely difficult.