You seriously think so? Casual sex has been a major use of Facebook for quite a long time. This particular approach may not catch on, but I guarantee you that some variation of this idea eventually will work.
I don't think casual sex has been a major use of Facebook for a while- certainly during it's college-only days that could have been the case, but less so in a more social network aware world.
I think something like BangWithFriends is doomed to fail simply because of the visibility. People can see if you use the app, which would embarrass many. And like almost every single online dating/sexual site out there, the number of men dramatically outnumbers the number of women.
That doesn't mean that a majority of participants want to publicly identify themselves as such, with the default privacy settings and erosion Facebook encourages.
Perhaps if it was more subtle and used less targeted/classless language.
After seeing this thread, I tried looking for ways to do bangWithFriends in a cryptographicly private way. Eventually I googled "bangwithfriends cryptography" and the first result was this thread.
You seriously think so? Casual sex has been a major use of Facebook for quite a long time. This particular approach may not catch on, but I guarantee you that some variation of this idea eventually will work.