One liquor store in my small town has a small rack with Playboy, Penthouse, Club, Hustler, Fox, Playgirl and a couple of others. Some distant cousin in MO owns(or owned, haven't been that way in a while) a small liquor store that sold a couple of magazines and had 3 or 4 crappy porn video tapes for rent.

Nothing big, but in my small town that has no adult store(unless you count the Movie Gallery that has a back room), I'm sure the magazines sell pretty good. I'd imagine in a bigger city that has adult stores, they probably wouldn't sell enough to even bother.