Gambling can never become an investment. Only way is when you invest in a gambling website. So whatever the profit the owner makes, you can get a part of it. But of you meant by doing gambling, gambling and investment are not even close.
You're wrong gambling can be investment it how only you use to spend your money and besides you don not need to gamble for it you only need to invest in the new casino's or gambling site bankroll when it is about to start that way gambling is like investing .By playing gambling it is not to be called investment it is the true meanin of gambling.