This can be groups focused on overcoming addiction or it can be online groups discussing overcoming addiction and of course, it really all does boil down to simply agreeing not to do it and not doing it.
Is gambling included to that "several addictions"? I think not. Gambling is something that is common and accepted by the society unless the gambler himself has lost control. Even if you are surrounded by people who had never even held a card, a poker chip, etc., and they see you gambling, they will do nothing. They will just accept the fact that you're gambling. Gambling isn't like doing drugs. If someone sees you doing drugs, they will automatically look down on you and/or report you (in some cases).
i believe that although gambling addiction is so much different from other forms of addiction but still there are many similarities between them and in order to give up gambling or staying away from it you can choose the same path that you choose for other forms of addiction to stay away or give them up. the core of the problem is somewhat similar.