People who go to McDonalds, or buys a Coke, or any other purchase made with those type of games attached, have something tangible, meaning, they can actually hold it, touch it, feel it, even taste it. Gives them a good feeling, fills them up.
Coming to a Sweepstakes shop/store/business, what do I get for my money? A card for gambling. You said yourself, "it SIMULATES a Las Vegas style game so it looks fun. In the end, just like the soda cap, you may win or lose." At least at McDonalds, I have enjoyed a sandwich and fries. or a Snickers bar, or Mt. Dew. I look at these as extras. Didn't have to pay for them, they were attached.
I could care less about these places. Went to one, not impressed, after Leo Daniels posted about the odds and how the machines are set to pay only certain amounts, I'd think twice before going again.