As you pointed out, eBay pays per click. I also think there is a commission for sales/won auctions that originate from those clicks. Amazon has a rate structure for sales related to your ads. I've only had the eBay ads on my hubs for about a month and have gotten more money from four clicks on 3 hubs than I've gotten for all of my Amazon capsules that I've put on just about every hub (over 50) that I've posted for the last six months. Amazon starts with a 4% commission for the first 6 or 7 items sold. It goes up to 6% after that. I've not gotten enough to worry about higher brackets. Hope this helps. Of course, different people might get different results.