Rank Suitors
In typical dating sites, people are matched to other people. But in reality, some of us think about the other person in terms of ranks.
"I'd first date Q before I date Jeff, and then Vinh, and then...," (just as a hypothetical example, if these were the only persons left on the planet to date)
This ranking information is very interesting and can provide loads of fun for users of 2rb.
So a feature using ranking might be for a user to be presented with a random mix of people who are secretly admiring her and users that are results from basic demographic match. (This would hide the secret admirers but still get ranking of actual suitors)
And then the suitors will be informed of his ranking, so that he knows where he might have the most chance.