Is there a reliable metric to use for that, though? I feel like it will be a tricky standard to use, not to mention that the users could argue that the casino abuses it because they won too much or something else. While it has good intentions, the chance for abuse is not small either. I'd rather let them offer a way to self-exclusion even if it isn't that effective. At the end of the day, the responsibility to control their activity lies with the users themselves.
I'm not sure how they use it exactly but I think they are using it on losing user, for instance lose a huge amount and then deposit and lose again and that happen in short timeframe but this is just my assumption, I'm not quite sure how they do it but yes, most of the gambling sites have self-exclusion features which is quite effective if the gambler is aware that he is getting addicted, on which we all know, they're not aware of.
I want to understand something very important from here because most times the self-exclusion do have features where a user has to choose the duration of them to self exclude. But again read somewhere about a user raise a case against a casino for reopening their account after they have self exclude themselves from such casino. Usually the gambling site should throw more light on how it works on their site to enable those who wants to self-exclude themselves to know how it works.