It's confusing to me that amazon is in the ads business at all though. They're a retail service, not an ad business and it seems that all the ad business does is burn goodwill. They do have goodwill to burn, but it cheapens the entire experience.
How does the saying go, again? "You may not be in the ad business, but the ad business is in you"? Something like that? That sounds wrong, but sometimes it seems like the double entendre may as well be the reality.
Per the article, in exchange for that goodwill they get a billion dollars per week. Do we need more explanation?
To be clear, it's gross, but they are doing it just enough that their convenience and average sufficient product quality keeps me using them. I'd guess they do a lot of research to keep that balance where it is.
How is it confusing? Most brick and mortar stores show ads for specific products. Online platforms other than Amazon do it too.
The only thing is that Amazon is more diversified than other retailers, in particular, they have AWS, essentially selling the platform that runs their website to third parties. It makes sense for them to offer sell their ad service to third parties too.