Should be strictly avoided, the casino type of investment will not guarantee full profits. Better to play right away than invest in a casino, I've tried that in the past, investing in a casino doesn't give me any profit, for example today I get 1% profit tomorrow I lose 1%. It just spins in place, at worst ever my money no left at all.
It depends on our own preferences, some people prefer to invest in the bankroll than gambling against the house and vice versa.
Investing in the bankroll should be taken as long term investment, you cant judge it by just 1 day or week result of your investment.
What you need to understand is that there is always a risk and you should aware about it and ready to take the risk no matter you are investors or you choose to be gambler.