That's actually not bad.
You're going to have issues with girls submitting stuff without IDs and releases, though --- you'll either have to
1. Shoot it yourself and collect the IDs, etc.
2. Be based overseas where it's not as much of an issue
And shooting the material will take lot$ of buck$.
Maybe you can do a JV with a porn company, but chances are since you're bringing almost nothing to the table except the idea and domain, you're not going to get very far.
I'd look for a JV partner who can bring some bucks to the table for this one - even if you have the content, you'll need to find traffic too. Not easy these days. It may just end up being "one of those great ideas" - but good luck with it, it really *is* a good idea.
Edited by OP's request.