Not every program out there is suitable for everybody. Depending on the amount of time you have and the amount of money you're willing to spend there may or may not be an affiliate program that works for you and not somebody else or vice versa. Some sites offer a variety of programs to preview before jumping in head first. Try this one http://www.joshuaglobalmarket.com
I agree. There are various kinds of affiliate programs that are suitable for various businesses. For some businesses pay per sale is good and for some pay per click is.
Your statement is really true! I have worked out a system myself to filter the winners from losers so that I do not waste time on lemons among affiliate programs and products.