Social networking has never stood on its own. When Facebook and MySpace debuted, it wasn't the thrill of social networking that brought people to them. It really was the opportunity to connect with similar people - people in their industry, people at their college, and people with the same hobbies and interests.
Facebook never had a need to cater to these groups individually, and that remains true today. To say that it has to work as the primary front-end tool for street soccer players as well as their mothers is equivalent to saying that Google Search has to meet the specific needs of every niche group who uses it to find the things that interest them.
Instead, Facebook has been quietly at work collecting a great deal of information about us as people. The few hundred million people on Facebook must be significantly easier to archive and catalog than the billions of sites that appear on Google. Should Facebook take full advantage of its function as a repository of personal information - serving as the Google of people - it would have no difficulty finding its own niche as a sort of meta-social network.
This integration has already begun. The thing is, it's invisible on Facebook itself. Instead, it can be seen on the Google search results for "login using Facebook," which shows some 750,000 results; or the search "facebook connect," which shows nearly 37 million. The sites you can use your Facebook credentials to log on to include runner's site The Run Around, lifestyle site DurianSeed, and the site for a pair of DJ's known as the Super Mario Brothers. Virgin Airlines, too, announced plans to use Facebook Connect on its planes.
What does this mean? It means that no matter what tribe you belong to, the data that makes it work can run through Facebook. Facebook makes logging in to any site easier; it means you don't have to re-enter numbing amounts of information about yourself; it means you can more easily find the friends you already have at the niche sites you join.
Maybe this will lead to better targeted advertising. Maybe it won't. But the functionality provided as Facebook invades every tribe on the Web is undeniable. Whether it serves as a search engine, a profile repository, or something else, Facebook is sure to stick around.