The fact that Amazon just drastically reduced its affiliate fees is perfect evidence of how little negotiating power these individual sites have in this value chain, despite their collective importance.
My bigger gripe is with the chosen business model. For comparisons sake take a look at Wirecutter. Their model is more aligned and a win-win-win for everyone involved (a free website with customer benefit that generates at least $30 million per year). Affiliate marketing has less hurdles and just feels more Internet-like.
Amazon’s affiliate marketing community is another cohort that undermines Amazon’s quest to increased profitability. And while Amazon may never retract the program in its entirety, it’s very possible that a reduction in commissions will follow as their own demand gen operation shifts into high gear