Either you put a demo and it interests me enough I might remotely consider logging with Facebook ... maybe. Or you accept fake accounts and be thankful for a lot more feedback from HN. By being greedy you have more to loose than to win.

I really don't understand the Facebook deepthroating trend. But feel free to ignore the advice that have been repeated here times and times again.

What sort of demo would make you likely to log in with Facebook? Screenshots of people you might meet?

Not the OP, but pictures of people tend to be a negative signal to me, as though someone's trying to use stock photos of faces to lend unwarranted legitimacy to their site.