What would this look like?

A social network where you had to implicitly prove that you provided value to people before you were connected with them.  Everyone of your “friends” was guaranteed to have listened to your advice, in a meaningful way, at least once in the past.

The growing fragmentation of social networks seems to show that people have different tools for tending to their core/aspirational audience (RSS/4sq for me); their broader but relevant audience (RSS/Twitter/FB for me); and their “signal” audience (the people they want to denote social relationships with — LinkedIn and Facebook for me).

What tends to happen with successful social networks is that they have a core value to the first user and some incentives to connect with friends (LinkedIn, for example, is a great place to store your resume in a web friendly way, and becomes more valuable with better social proof).

Facebook’s got a broad ownership of your entire social graph (how you connect broadly to companies, products, people); if you want to build a social network, don’t compete on the broader data play — what niche information can you get detail and clarity on that users or marketers care about?

I’d find a network of the people that you actually influence to be useful as your friend (linkedin fails at this for me right now).

What other more clearly defined data would be a valuable asset to build?