Why should I even care about their data model as a costumer? If any other seller would pull a trick like this: "sorry, my supplier provided counterfeit items - I have nothing to do with it", they would be f-cked anyway. If Amazon stores, Amazon sells, Amazon ships then Amazon is responsible. Try to order some counterfeit iPhones from China and sell them on local market. When authorities come, give them an excuse: "look, it's an Apple logo on it and supplier told it's really iPhone, it's not my fault this item is counterfeit" and tell us how it went.

That's technically true yet also irrelevant. Amazon fully controls all aspects of sale.

With other categories that Amazon decided to care about, like toys during Christmas, they put controls on who can sell them and has qualifications to make it harder for a bad seller to just reappear.

In a major category like headphones and power supplies, the company takes a Casablanca style "we're shocked that there is counterfeiting going on here!", although it's not credible that genuine product could be sold at the price points they are selling for.

Another issue of letting sellers glom on to the main product SKU listing is that the reviews are all over the map, and there's no way for a customer to tell which review came from which seller.

I bought some tripod mounts for a VR rig - some of the reviews said they were plastic, some said metal, some said the quality was good or bad, etc. I rolled the dice, and got metal ones that smelled so badly of gasoline that I couldn't keep them in the house. Ended up buying some name brand, that at least had predictable quality.

There are lots of things that Amazon could do to counter these issues. Just look at what they are doing for Prime and 'sold by Amazon' - there is a big checkbox when searching to only show prime-eligible items, and when looking at the list of sellers, amazon is shown prominently with different graphics. They could easily do the same things for verified owners of products, so that OEMs could sell on Amazon and customers could be sure they're buying a genuine article.

If it were truly an insoluble problem, why are there no 'Amazon Basics' counterfeits on the market?

>they ought to do something about the naughty seller who's trying to pass off the counterfeit item as if it's the actual Product.

Which is a problem because how can they hold the seller accountable when they co-mingle items?! They need to barcode and track every item sent in for co-mingling so they know exactly who to punish.

ADD: If the items are co-mingled and I send in a legit item, another seller sends in counterfeits, a buyer chooses my offering because I sell it for less or because I get better reviews, but the item is fulfilled by Amazon, and Amazon just grabs a random item from the SKU bin and sends the buyer the counterfeit item, there's a possibility that I get punished and blamed for something out of my control. Yes, I could pay more to not co-mingle but why should I have to pay to solve Amazon's problem? They either need to track all items sent in or require non co-mingling for everyone.