The way private label grocery works is very different. Private label CPG products are developed through partnerships between the retailer themselves, consultancies like Daymon Worldwide (now owned by Acosta), and producers (often called copackers in this instance). Depending on how commodified the product is (like canned corn or frozen vegetables), it might be simply a matter of white labeling and sourcing through reverse auctioning. Sometimes the retailer will work on the product development lifecycle to create unique offerings.
Generally speaking, these copackers do not pay the retailers to get into their store, because the retailer is paying them for these products, and the retailer is possibly sourcing at least the packaging if not the development on their own. Whereas Amazon acts as a platform, retailers actually purchase and take possession of the product that they have had some hand in creating. Essentially, PL (private label) products start much further back in the supply chain. By the time they reach store shelves (even by the time they reach the warehouse), the supplier has already made their profit. You would rarely if ever have a brand in a store that gets upgraded (or downgraded depending on the power of the retailer's brand) to private label due to sales considerations or lobbying on the copacker's part. If anything, the retailer might take on lesser known brands the copacker is trying to promote as part of their sales agreement, even though they could be the same exact product that is in the retailer's branded packaging.
Speaking to Sam's Choice specifically, as it relates to Amazon's Choice:
- Sam's Choice is only tied implicitly to its retailer (at least as far as Walmart is concerned, at Sam's Club I'm sure the connection is far clearer). You need knowledge about the organization (or to read the packaging) to understand that this is a private label product. Amazon's Choice is much more explicit.
- Amazon's Choice is a designation more than a brand. As far as I know, the products retain their own branding and identity. Most customers understand that private label products are not manufactured by the retailers themselves, but if you want to find out that Sams' Choice (and much of the private label soda and soda adjacent products category in the majority of food retail) is actually manufactured by Cott Beverage, you need to do some research.
- The idea that Sam's Choice was "created" by Cott is kind of strange, though I can't dispute it directly. PL brands like Sam's Choice (and Great Value, Walmart's other PL brand) are owned by the retailer and usually entail working across multiple categories, which means working with multiple suppliers. It's possible that "Sam's Choice" the brand was created early enough during the evolution of the PL ecosystem that Cott coined the name of the brand (even though its almost a complete copy of President's Choice, the PL brand of the Canadian supermarket chain Loblaw), but to consider a PL product a "third party" product is very strange to me. Cott doesn't have any claim to Sam's Choice products that are produced in non-beverage categories.