1. Amazon Direct Fulfillment (dropship): Order is shipped directly from the manufacturer to the customer. Amazon pays for the shipping label and contractually "own" the item once it leaves the MFR doors. Amazon incentivizes Manufacturers by paying the freight and loosening shipment deadlines. [1]
2. Ships In Own Container (Amazon SIOC) certification puts the responsibility on the manufacturer to certify their products can be shipped without extra packaging. MFR pays for the testing/certification from a third-party. After July 3st 2019, Amazon will charge/fine manufacturers $2/unit received that are NOT SIOC certified and greater than a certain dimensional threshold. [2]
Its a tough economic balance for Amazon because they want to keep shipping stuff, but many MFRs will literally stop selling items to Amazon on July 31st because the costs of SIOC certification are greater than the estimated product profitability.
Source: I am a consultant for Manufacturers that sell to Amazon. [3]
1: https://www.andersonassociates.net/guides/amazon/what-is-dro...
2: https://www.andersonassociates.net/2018/frustration-free/