Despite the fact that "Greed" is human nature but it is the only word which is enough to explain gambling addiction.
I agree that only a single win can lead to addiction if a person can't control his/her emotions.
Indeed greediness has the ability to trigger gambling addiction. Most at times, gamblers get into losses because of greediness and when trying to recover their looses they get into addiction. Looses cannot be recover in gambling, what is lost is lost, as an attempt to get it back welcome addiction.
That is true. We see many people become greedy when they saw a chance to win and they will make a big bet in one time. But their plan doesn't always work because it will be difficult to beat the house if we don't have luck. They cannot control themselves in gambling, and that will trigger them to spend more money because they hope that in the next round, they will win the game.