I suggested this a while ago to the stafff but they didn't like it so much. =/
Actually, I suggested some type of arcade-place or amusement park where we can win coins. They didn't like it because they were afraid everyone would just get a billion coins in one day and buy out the shop.
The only reason why I'm opposed to slot machines is how incredibly difficult it'd be to win. Like, you see, someone with few coins would have a VERY hard time ever earning anything, as he'd probably lose all his coins without profit, whereas a person with lots of coins can accept a long period of loss and still manage to land back on his feet.