I can give you a few tips on what affiliates seem to like/dislike:
- rep having atleast some technical knowledge (enough to answer some questions...not just say I'll ask tech and get back to you)
- quick response time and online availability (I'm talking ICQ here ;p)
- when you tell them something will be investigated or fixed, make sure it is
- don't lead them on saying 'we dont have it yet, but can do it for you' if you are not going to actually do/add it
- don't harass them. following up when its a new account, or they tell you about a new campaign or something is fine. asking them everyday why they aren't sending more traffic yet isn't.
That's few of a long list of top of my head
