The biggest reason why the gambling is more successful business and it is always risk for the gamblers when the gamblers win the bets they will play for more to earn more but repeating the same winning is not possible for many times so they are going to lose more money than winning and the people who lost their bets keep trying again and again to recover from their loss so they also going to lose more money if they play more.
I guess its human nature that when they start to win, they will continue and will not stop until they feel they need to stop like when they don't have money anymore. Self discipline and self control should be practiced at all times. If I play in real world casino, I would bring someone with me to remind me when to stop. Online, I would set a limit on when I need to stop and access to my extra funds should not be within reach.
That's a good technique, a person with no discipline will not stop until they have nothing to gamble anymore.
Gambling is a good way to entertain ourselves but it could also be a way to ruin our life, the bad thing is we will experience more loses than winnings
so we should learn to control so gambling will not affect our daily living.
More precisely the greediness of the person causes the people to lose more money in the gambling so self control is what needed when they are entering into the gambling and like the above comment says they need to bring someone for casinos who is not a gambler or set the limit for themselves.