earning from gambling depends on your luck and selfcontrol, you could win or loss millions in short period
there is no stable and regular income guarantee
you forgot to mention bankroll management. it was an important thing that people always ignore.
it's okay luck factor are the number one thing that make gamblers win and earned, and selfcontrol i can assumed that is a control to stop play or even quit gamble once hit a huge winning like won a power balls jackpot etc.
and bankroll management was in third place on 3 important factors determine our earning from gamble for me. without this, we could gamble like a mad and lost money that we can't afford to lose.