Not a whole lot actually. Some guys go there to watch sports while getting attention from attractive girls in short skirts, revealing tops, and for the most part larger in the chest area. All the guys that go there get attention from these women whereas they might not get attention from women period in other areas of their life.
What you might try doing, if possible, is locate the January 2009 issue of Playboy. It has Carmen Electra on the front. On page 108 is an article you should read that relates to your question quite well, about a guy going to a bunch of Hooters restaurants.
And yes, this does mean that some guys do read Playboy for the articles. I'm not sure of the percentages, but it does happen. :)
Hooters is basically a TGI Fridays-style restaurant with crappier food. Its big claim to fame is that the waitresses all look like playboy centerfolds and dress in skimpy outfits, and that's their big claim to fame. Supposedly they also have really good wings but I'm not really a wing person, all I know is their burgers suck compared to TGI Fridays.
It's a fun place where you can get good food and hang out with fun, friendly and cute girls in outfits that don't look at all silly. It's one of my favorite places. Perhaps the best part is that you don't have to worry about whether the vacuous stare you received from the waitress means she got the order right since all the food is terrible anyway.
It's just a restaurant. Beer and wings. But the appeal is the near-perfect women that work there, and wear teeny shorts and a tank top (it's rigorous to get hired on; you have to be exceptionally beautiful). That's it. Guys like to go there to have wings and beer with the boys, watch the game, and check out the hott girls during commercials.