For a day or so last week, Jeff Bezos passed Bill Gates as the richest man in the world. And that's pretty much how he did it.
Bezos runs Amazon, which is primarily a shipping business. It relies on the U.S. Postal Service to deliver two-thirds of its packages. In many places now, it locates a depot near a post office, presorts the packages, and delivers them to the post office. The Postal Service, which has a monopoly on last-mile delivery, does the rest.
The Postal Service is happy because it can report healthy increases in sales in the package delivery department. Postal employees are happy because it means work seven days a week — the Postal Service operates on Sundaysalmost solely to deliver for Amazon.