The new "customers" at the center of Amazon's business model are a global assortment of insta-merchants that don't make the products, don't handle their own logistics and don't have recognizable brands. So -- whoosh! -- in comes Amazon as the ultimate partner/toll-collector. For a fee (or actually for many fees) it will shine up these impostors to the point that they can conduct a lot of business on the Amazon platform.
When Amazon provides distorted search results, my hunch is that it's providing boosted listings for whatever pseudo-merchants are willing to pay up. Or that have agreed to buy other Amazon services. And, hey, Amazon is going the extra mile to make them feel well-treated