How is that even possibly true. So if a seller sends every 50th product with a brick instead Amazon would only be able to track it in the first steps of the logistics chain?
I misunderstood my sources, I've edited my original reply. Between buyers not necessarily getting their seller's stocks, sellers not necessarily getting their own stocks back when requesting a return, and the apparent lack of action from Amazon until now, I added 2 and 2 and got 5.
