[Volscio]

Just because your friends aren't on it doesn't mean it's "single-player", since you have visibility with other people who live in your city -- I have in fact met people solely because we friended each other or traded mayorships through Foursquare.

Also I'd question how many people use Foursquare to meet up with friends. Are you saying that friends meet up at locations not because they set it up via email or Facebook or Twitter beforehand, but because they were in a location randomly and saw a friend in a nearby location? What if they weren't invited?

I don't think you really understand how Foursquare is actually used.

[WiseWeasel]

I'm saying that you see when a couple friends check into a social meeting location, and say, hey, that location is near me, and seems like a good time, I think I'll check it out... Or maybe you ask yourself where everyone is on this Saturday evening, see that all your friends are checked into a local party spot, so you immediately know where the action is. I don't see using it as a way to make new contacts through leaderboards and achievements and such, but I'll admit I'm not all that interested in meeting new people through such a geeky venue. Might as well go all out and join a D&D club at that point.