The algorithm is quite doable. A good-enough algorithm would be fine -- I have higher standards for those I exclusively date than for those I grab an occasional beer with. An opportunity to meet some new and interesting people would be great.

The viral loop probably lies in encouraging people to sign their existing friends up so that we can better classify the kind of people a user gets along with. I think people would use it, given that it had some mild game mechanics and some real social benefit. I'd push hard against making it in any way useful for dating and hookups at first, otherwise it would quickly get a stigma.

I had an interesting chat with some salesguys a couple of months ago, where we talked about an application that lets you say, "I'm in Denver on a layover for four hours. I'd love to grab a beer with somebody who sells into the enterprise software space and has some time to chat." That's one possible revenue source. Permission marketing is another one.

If I were to go the social-media-startup-route, this is the problem I find most interesting.

http://www.njl.us/social-networking-but-the-other-way-around