Any vendor that is trying to steal sales is silly. The way a vendor could steal a sale is by having a leaky sales page with contact info on the sales page. Then prospective buyers could contact the vendor directly. But, if the original cookie is still on the prospective buyers computer when the purchase is made, the affiliate still gets credit for the sale. Personally as a vendor, I want as many affiliates making sales as possible.
Well.. There are so many crooks in clickbank, that there must be an alternative. Sadly, The current alternatives are worse. SO MANY VENDORS SHAVING AFFILIATE LINKS, or even worse, collect email addresses and link to similar clickbank offers with their affiliate links. I can say I saw a few that were very clever. Always check who you promote. (16 times). I recently promoted a product, sent 200 targeted (sale oriented keywords) clicks using adwords, and nothing. Then I realized this fucker was redirecting to a paypal page on another domain. Thats the problem with clickbank, no one monitor anything. and this is the best we have.
So being affiliate with CB is good money, if you know how to save yourself from these thieves. BTW- does anyone face the same problems with CJ, Amazon or any other ?