Apparently UPS+USPS can not keep up with growth of Amazon sales,
so before drones, now there are Amazon trucks delivering...
Out of 500K Amazon employees, more and more are driving trucks.
Amazon Is Testing Its Own Delivery Service - Business Insider
"Amazon could be rolling out its own private delivery network to make more same-day deliveries and have more control over shipping expenses "
AMZL US - Amazon ships products using their own Shipping Carrier - Tool Craze
Deliver With Amazon (logistics.amazon.com)