Some casinos will also try and stop you from registering their brand names and have it as part of their terms and conditions – although whether it is enforceable, i don’t know.
eg top-888-casino.com (not sure if this is a suitable example)
What I am getting at, is that if you rank your top-888-casino.com highly in the engines, the casino might say you are encroaching on their trademark brand and request that you hand the domain over.