You will seriously need to expand on these points to get customers. Looking at the idea blind, I can't see how it can be any of these things. No pretty UI stuff will be needed until it's a viable business, and addressing these three concerns strikes me as paramount.

1) realizing that my original idea sucks and that it needed to evolve or completely change

2) realizing that even if my idea is good, most people are either indifferent to it or they hate it. Which makes me think of this quote, "Don't worry about people stealing an idea. If it's original, you will have to ram it down their throats."

Neither experience is pleasant. Both are morale killers.

Ideas are cheap.

Why am I pointing this out? Because I think my attitude represents a huge chunk of Facebook's users, and I think most of what's left over after you subtract that chunk consists of people who don't care about privacy period.

I use LinkedIn for business. I use Twitter for geeky stuff. I use Facebook for non-geeky stuff and to post pictures of my kids in their halloween costumes. It all seems to be working out OK for me.