I use few eBay capsules in my Hubs but had been using quite a few Amazon capsules (particularly before I was approved for a Google Adsense account). Amazon rewards well if a reader clicks on the ad and PURCHASES the item. I get clicks, but no purchases. Therefore, no Amazon revenue.
I think if you write review Hubs or special niche Hubs with target Amazon ads, you may sell a few products and make some money. But, your Hub has to really make the reader want the item. Then, if you offer them the opportunity to purchase it right then, they may do it.