The story of Microsoft's evolution brings excitement and anticipation to new companies and ever changing industries. Microsoft started with a vision of supplying products, made its fortune on it's Windows platform and has now also offers services. It dominated the OS, tools, application and networking layers, and then used it's clout and partnerships to further vertically integrate.
Facebook is following a similar path in that it has dominated social media and along the way has become an expert on cloud services and infrastructure management to manage the massive amounts of data they have. There is much speculation that Facebook will begin to offer enterprise software, creating a solution for a new layer where a need already exists.
Establishing expertise in one layer often leads a company to develop "side effects" or unique strengths that are applicable and needed in an advancing industry.