Fair enough. So there is Amazon the retailer. That is what Amazon originally did - buy inventory from vendors then sell them. As Amazon gained scale they launc

Fair enough. So there is Amazon the retailer. That is what Amazon originally did - buy inventory from vendors then sell them. As Amazon gained scale they launched 3P aka 3rd party selling. This is essentially Ebay at scale. Returns for these products are more or less managed by the seller. FBA then came where 3rd party sellers can take advantage of Amazon's delivery and warehouse logistics. The stock is held by Amazon and can tap into Prime delivery. IIRC returns are also handled by Amazon so you get no questions asked returns. I will usually filter products by Prime and will then usually look for the "sold by Amazon" text on a product page (as opposed to "Fulfilled By Amazon") In the same way I think twice about buying random things on eBay, I also think twice about buying 3P (and FBA to a degree) on Amazon. Filtering out 3P on Amazon is fairly straightforward. Filtering FBA is more manual and takes reading of the page. If fake inventory is being comingled that becomes impossible. Amazon the retailer is (from my experience) reasonably priced, delivers goods in a day (sometimes less) and offers me a return policy that is hard to compete with anywhere else. I would never buy cables or batteries from a 3P seller. I would think twice with a FBA seller.