Here in PA, it is legal for businesses to give away beer and you don't need a liquor license to do it. But it has to be free with no strings attached like "free with purchase" or they label you a speakeasy and fine and arrest you. They send undercover people out to verify that you are giving it away and carding everyone. (Apparently PA pays someone to go drink free beer)
I had one of my locations try this tactic to get people in the building. Every Sunday afternoon, they would get a keg of beer and turn on whatever sport was on that afternoon. As I carried my games out after they closed I truly wondered how bad you had to fail that even free beer couldn't get people in the building.
(disclaimer, it has been a few years, the laws may have changed since then, I am not a lawyer and check with local laws before trying it in your business and it may not help anyways)
Quoted from Joe_Blasi:the japanese pachinko places do something like that to have the prizes exchanged to cash.