Gambling and Government

While I was wandering through downtown Detroit, I went through Greektown, and saw several blocks of revitalization around the Greektown Casino.  It made me wonder.  Why can a casino stimulate development in an area where government probably can't?  Why would people willingly come to downtown Detroit to throw money away, when they'd never want to pay taxes to the government?  I assume it is because they think they can hit it big, and they have fun trying.  Therefore, since 46% of people don't pay any federal income tax, but they have to file a return to get a refund, why not offer a huge raffle for these folks?  Say, $100 for a chance to win one of 50 $1,000,000 prizes?  You would only need 500,000 people to participate to break even.  The best part of the whole deal would be listening to the winners bitch about having to pay taxes on the prize.  Or, maybe even more interesting, a giant 50/50 raffle.  How big would that pot be?