That's not how the idea of distributed social networking works. At least not distributed FEDERATED networking. I haven't seen anyone saying "Join my social network, it's better because it's mine." I see people saying "join this social network because it is YOURS and it can work with other networks" (through connectors or the native protocol.
You sign up for Alice's network, you friend the ten people on Bob's network, and the 35 on Charlie's network, then when you hit your feed page (On your node) you see all the posts shared with you from your friends on Bob's network, Charlie's network, etc. All of your agents (nodes) communicate and send data around on your behalf (shares, likes, posts, pics, videos, events, etc).
It's like E-mail (Or XMPP). You have an identifier that "belongs" to you, and an agent (your node) that works for you. It aggregates everything you care about (And everything anyone cares to share with you) and presents it to you. You don't have to do anything special. And anyone can find you based on your identifier.
I'm not totally on-board with Bennett's platform, mainly because if there are ANY costs implied or associated with running your profile, that will strip out a good 80% or so of the people who would participate. Think of all the people who go bonkers when a "Facebook is going to start charging you" message hits the wire.