I don't know about other sponser programs but the one that I run for my paysite which is
True Amateur Models has always paid my affiliates every week and on time. The program payments are issued out through CCBill and if you are interested in promoting high quality amateur content then be sure to check out
True Amateur Cash.
As far as a drop in sales, that has not affected me at all. I am getting just as many sales as I have always had. In fact, the sales still contiue to just go higher and higher as time moves forward.
I shoot all of my own exclusive content and the webmaster program pays out 50% in commissions. There is a 10% webmaster referral and lot's of free hosted galleres to promote too. Here are a couple of samples. Many more are available after you sign up with the program. Hardcore and softcore are both available for promotion.
http://www.trueamateurmodels.com/two...ling-nude.html
http://www.trueamateurmodels.com/nud...teenjenna.html