TLDR: Avoid at all costs
KeyAffiliates used to be a fantastic network for gambling offers. They'd convert well, the AM was super responsive, and they'd always pay on time.
Not so much. The AM takes literally a week to reply to just about any message (especially true if it's about payment), the offers aren't very stable (new offers are removed within 1 month), and you'll be lucky to get paid when you're supposed to. I stopped traffic with them 100% after my last payment, which was less than half of what the AM said I would be paid (he even confirmed it multiple times over Skype).
I've never received my "prize" for completing their quests for meeting certain milestones, either.
I would not advise anyone to sign up for this affiliate network. They seem to be having financial issues, seeing how many issues multiple other people are having getting paid on time.