I too make money from Amazon BUT it is primarily via ebooks and the like... Hey you writers, WRITE a novel you know there are a few good books lurking around inside you!
I recently have been doing well with Google AdSense, better than years past, there is something to be said about mature content and Google Ads are trusted by readers. Gear pages more toward a basic need and let Google do the work. I still use Amazon ads, there are still a lot of people out there who use Amazon for purchases yet not willing to cough up the @ 100 bucks annually for free shipping, everyone offers free shipping, well it is more common.
It is the younger demographics that buy without prime accounts and other retailers online. The opportunities are out there perhaps take down a few Amazon products, limit them to one or two per page and focus more on content. I know we hear that a lot but CONTENT is still KING/Queen!
Best Regards to ALL in 2018