What Walt said is true... and, I might add, you might want to make sure that you don't have any warrants out for your arrest before you go, if you decide to go. Sometimes law enforcement agencies use this tactic to clear their arrest warrant files.
I received a blue card about two weeks ago claiming that I had won a new car or $49,000 in cash and a trip. I did some research and found most people said it was a scam but no one had gone to the appointment. I decided to go. First, what the sales representative said was going to be an hour and a half appointment was more like two and a half PLUS two hours of waiting for your turn. I really wanted to know if I would get my prizes because I had noticed that a lot of other people had walked out during their appointments which means they forfeited their prizes. I repeatedly said that I was not interested in buying any time shares and they finally said okay and that I could go pick up my prizes. I went to a little office and got a scratch off ticket with 25 boxes. I got to scratch off five of the 25 boxes. (If you scratch off all five pots of gold in the 25 squares then you win a car or $49,000.) of course I didn't win the car because that's pretty much impossible. However I did "win" two trips, one trip to Las Vegas or Orlando (hotel and airfare included for two) and another trip to Hawaii (hotel for two, airfare not included).