There is nothing wrong in gambling, unless you used all your money up on gambling and you still play and get huge loans that you couldn't pay for, then that is when gambling is wrong
The moment we decide to make money from a gambling site is wrong already. We cant make money from a gambling site but we can always play for fun. If we tried to make money from gambling site, eventually we are going to lose. We could lose small amount or bigger amount but losing money from that kind of stupidity is wrong