I have to agree regarding clickbank -- they were one of the first I signed up with years back and at first I was all fired up about it. Even purchased a script to sell multiple products on my own web site and put my heart and soul into promo'ing mine AND selling others.
I jumped ship a couple years back because when I would make sales, I would soon have nearly half of them credited. One of the thoughts I had was that people would read the eBooks they downloaded and then want their money back.
The same thing happened with my own products. I never get returns now, but when offering instant downloads, again about half of my sales requested refunds and in spite of my no-refund policy, I had to thanks to Clickbanks requirments. I felt I was held back from running my business the way I saw fit.
I could go on and on, but will spare you. Suffice it to say, I wouldn't suggest clickbank to newbies, either. You're sure to get more frustrated than anything.
