Now, call me a weirdo if you want, but I'm the kind of fellow who would sort of like, maybe, just the tiniest hint about what a site might be before I sign up for anything. Sure, you have the word "social" in the URL and the site title -- but what does that mean? What's in it for me? I mean, I can log in with my Facebook account, right, so what the heck does your site do that I'm not already getting from Facebook? (Not that I get a lot from Facebook -- I have an account mostly because the Second Cup coffee chain wants me to have one to use their wifi for free. Call that a hypothetical question, then.) What do your users share here that they wouldn't share elsewhere? Is it a niche community (or does it want to be one)? Can I make connections that would be difficult to make elsewhere (say in the way that Google+ circles offer limited distribution -- I can hang with my friends without it spilling over into my professional life or embarrassing my mother)? I just don't know.
There is some truth to the idea that a social site will become whatever it becomes, but it will also tend to become whatever your guidance/intentions make it. There's no clue to be had up front. The place really needs a sort of "mission statement" and a call to action when a new user (or anyone who isn't logged in) hits it.