If you are put your money on gambling this is not good thing. First of all Gambling is too risky play because in this you have too much luck for gambling to win and also if you put all money in these site or in casino and your luck is not on your side then you lose all money and all your income. You can play gambling for a fun not a living income.
If you already know the risks, you better not try to approach them. Otherwise, you will experience defeat, resulting in losing your money in both the short and long term.
But I don't know. The temptation of gambling is very big to entice us to come back and play longer. And maybe one day, the casino will ask you to show evidence for verification, including proof of source of income, because maybe the casino doesn't want to be blamed if someone goes bankrupt because of gambling.