Maybe I'm just socially inept, but I have never once managed to meet someone at a bar that wasn't already part of some bigger group that I was with.
Edit: that's actually untrue, there are exactly 2 instances where it happened in my life. They were in the kinds of bars that I would usually avoid (too many drunk people shouting over loud music), in areas far from where I lived, that had pretty strong "going out" cultures.
Edit 2: now that I think about it, I'm not exactly dashing handsome. I've historically done a lot better in "house party" type of settings, but again that's with people who are already friends of friends.