I believe providing a link to support resources is a legal requirement in the UK.
Beyond that, users generally have much more of a relationship with the operator than the affiliate site, so surely most responsibility has to be with the operator in terms of self exclusion, limits etc.
I've thought about donating to a support charity. I need to look at them in a bit more detail before deciding.
I feel terrible for addicts, but ultimately people come to my sites because they have made a conscious choice to gamble, and they are responsible for that choice.
Clearly support needs to be available, but I'm not qualified to offer it, so I think links to the various charities are much more appropriate. You don't see pub landlords offering support for alcoholics...
Interested in quality, relevant link exchanges and deals, especially with UK sites.