I mean, they own the whole platform so click fraud would be easy to get away with but hopefully that's not happening. I'm not sure if anyone has the ability to audit their honesty.
I can't speak for Costco, but that's not really true in a conventional supermarket though.
It's pretty well known that food manufacturers [can/are required to] pay to get better shelf placement (e.g. eye level vs. way high up or way down low): https://qz.com/807723/inside-the-secret-backroom-deals-big-b...
A phone wholesaler with a retail business will be broken up since it is a problem for their other retail customers.
This is quite similar where Amazon is acting as both the provider and a retail customer competing against their other retail (marketplace business) customers, with a number of advantages.
Having them forced to provide services at arm's length, at published costs, with audited public books and no inside information would level the playing field. They probably already account for advertising "spend" internally anyway if they're smart, since as another poster alluded they miss out on PPC when someone clicks on an Amazon product so need to know what it cost them.
Based on my last trip to the supermarket, absolutely.
The stores have to put their brand next to the name-brand, or nobody will see their stuff.
They can't just shove the name brand items to the bottom of the shelf because the brands have done all of the advertising, and those are the logos, colors, and packaging that people are looking for.
Display in a store is much more limited than online. They have to put like items together if they want customers to find them.
Why the sudden outrage?
PS: I didn't read the article because of what I consider an even more grotesque form of consumer manipulation...blocking your news website from displaying the full article unless you interact with it, and breaking reader mode so that you have to see their ads/graphics. I'd get my pitchfork out for that.