https://phys.org/news/2018-06-ups-truck-amazon-delivery-vans.html

With these vans on the road, Amazon said more shoppers would be able to track their packages on a map, contact the driver or change where a package is left—all of which it can't do if the package is in the back of UPS or FedEx truck.

Amazon has beefed up its delivery network in other ways: It has a fleet of cargo planes it calls "Prime Air," announced last year that it was building an air cargo hub in Kentucky and pays people as much as $25 an hour to deliver packages with their cars through Amazon Flex.