True, the goal isn't to kick back money, but the goal is to refer people to Amazon that wouldn't have purchased from there otherwise. They have good fraud detection systems in place to make sure that people aren't just using the affiliate program to give Amazon discounts to themselves, friends, family.

Ultimately Amazon does what every company does in some form or another as it scales--cut incentives, trim margins, increase on-site advertising, etc. It's one long life cycle game that plays out again and again.

The problem with that goal is that affiliate links are having less and less of an impact on convincing people to buy from Amazon, because Amazon is becoming the #1 place where people buy things anyway. If I read about something on the Wirecutter and I decided to buy it, I will buy it on Amazon whether or not they have a link to Amazon. Amazon knows this, and as they begin to dominate online sales in a certain category they can afford to drop their affiliate commissions knowing full well that it won't really impact their sales.

As someone that doesn't use the program but does own an etf that covers the market, it's weird to think that I benefit from this change - at most a penny or so.