I think that the thing that should set his idea apart from a website is that it has a highly structured data structure and restful API which allows the data to be accessed, aggregated, and presented in a myriad of ways.
So yes, you could have a standard “social profile” presentation front end which looks just like a geocities site, or Facebook page, or Friendster page or whatever.
But you could also add all your friends into a presentation layer that gives you a Facebook, Twitter, or instagram like feed, all federated from the single source of data they maintain as a federated social profile.