If a gambler can gamble with only small amounts he can afford to lose, not minding the fact that he might be winning small amount too, he will be saving himself from the dangers involved. Greed is the major enemy of gamblers, those who have conquered this enemy have nothing to worry about.
Overcoming greed is not easy if a gambler sees gambling as a way to earn money. Greed is always present in our personality so when there is a chance we are getting what we wanted, there is always the urge to want more of it.
Greed is only not an issue for gamblers that plays for fun and doesn't care if they win or lose the game. Their only goal is to seek enjoyment through gambling.