In my experience, private CPA deals generate more revenue than large numbers of affiliates. Many affiliates take no action after signing up for a program. Those who do use the affiliate creatives usually generate only a few sales here and there.
The fraud rate among affiliates can be very high, too. That’s especially the case with CPL offers.
I’ve managed affiliate programs, and I’ve learned that you shouldn’t approve every affiliate who applies. Look for affiliates whose sites contain high-quality content and garner a large amount of quality traffic. Also, affiliates who have large double opt-in email lists are excellent.
As long as you have a good affiliate tracking solution, you should focus your efforts on private CPA deals. Though they take longer to negotiate, they can be very profitable.
Note: I originally posted this comment in a LinkedIn group.