It sounds funny but it is really the way to self-exclude yourself.
Of course it don`t help, if someone wants to continue gambling - there are lots of casinos, where anybody can register(possible with some restrictions) with the same games, but if someone decides to stop - it can motivate at least.
PS. I don`t recommend anybody to but or sell accounts, it is only your decision.
I find it the same way, self-exclude doesn't help at all, it's just a decoration of a casino but it still depend on the will of the gamblers. It's true, we can self exclude ourselves in a certain casino but since create an account is very easy, we can always try playing in other casinos. I think the solution of addiction is stopping gambling, not fooling around ourselves that would only result to bigger problems. However, I don't blame the casino for having that kind of feature, becasue it's better than nothing at all, although it's not really too helpful.
It is only your decision to use such opportunity or not. It is just the tool. And of course it is good that there is such opportunity, even if i don`t believe in it. May be it can help someone.
But the way to sell account or delete it looks more serious - you need to find new casino. It is not a problem of course, but it may be uncomfortable.