I'd give them more than 24 hours, but 7 days should suffice for them to get back too you. I guess I'd also look an take into account, how long they have been an affiliate, and how productive they are. Let's be honest with one another, a good affiliate is hard to find these days
So no reason to piss them off by pulling the plug after 24 hours. Get with them and make sure they have access to good promo material from your site, and I'm sure they would rather use it.
The problem that your going to run into with them promoting your site with some one else's content, when the surfer does actually buy a membership, they can't find the content that they thought was going to be on the inside of your members area
So any sales you do get, are going to be limited in their profitability by how long the member stays a paying member.
I think we all know what the right thing to do is, the question is, how many of us will actually do it
Good luck with your dilemma!