I think the lack of a common name/URL is the biggest problem that is preventing federated open source social networks from gaining mass popularity. I remember when identi.ca came out as an alternative to Twitter. It seemed like it was starting to gain some traction, then they switched to pump.io and closed registrations. I haven't heard of anyone using either since. Look at Diaspora, that never took off either. You might convince someone to try it out, they'd go to the website and it'd be too complicated for them. "Which pod do I choose?" Then they would just go back to using Facebook and Twitter.