The following is what Scott Dieken had to say in response the the question, What is wrong with affiliate marketing and how can it be improved?
All affiliate programs should provide EPC data, instead of wasting our time promoting products that they have not optimized to sell themselves.
So they use affiliates to get a few sales.
CJ EPC data is nice, but not accurate. There is something wrong in the system. I can see it in my own EPC numbers – they are way higher then what I actually make.
I have been asking for these numbers since the 2000 Miami Affililate Force conference.