https://consumerist.com/2017/08/02/amazon-changes-return-policies-for-third-party-sellers-who-worry-about-fraud/

One of the ways that Amazon has been able to offer such a wide selection of items has been through its Marketplace, or third-party sellers. These businesses or individuals would ship from their own bookshelves, garages, or warehouses, handling order fulfillment and letting Amazon expand its inventory without building any new warehouses. Now a new policy makes it clear that sellers who handle their own orders are at a disadvantage.

CNBC reports that the change that Amazon announced to its sellers involves how returns work. If an item can be returned, the customer will be able to print a return label instantly, without having to first contact the seller and get the return authorized. This change applies to sellers who handle their own fulfillment, and who may not want Amazon generating free shipping labels for customers.