Looked into CPA yourself?
As I have been involved in CPA for some time and it appears to be something a lot of people are selling courses on and others are buying, I thought I would add my thoughts.
CPA can be very good indeed if you have either critical mass (lots of visitors) or a highly targeted niche where the visitors buy. This may sound obvious but its more interesting than you first might think.....
You see when CPA offers are paying out $0.50-$1.00...