The whole question is what attracted a person to gambling - the desire to earn money or the desire to have fun. If the former, then the probability of addiction is very high, because the beginner will try to earn something (and then it often turns into an unrestrained desire to win back). If the latter, it is easier. It is enough to offer an equivalent substitute in terms of emotions and andrenaline
Yeah, it is basically trying to reach for an ever out of range carrot.
Addicted gamblers will think they will win if they play just one more time.
Same as alcoholics, just one more drink. It's similar behavior.