So I've ordered a book from Amazon, and it shipped out on March 1st.

Tracking the package reveals only that it's on its way and should arrive around March 21st. Twenty days.

A Google search shows that the distance the package must travel by road is 1320 miles, from Salt Lake City to St. Louis. That's 66 miles per day. Which is 5.5 miles per hour, if you allow 12 hours per day for travelling.

So what does all this mean?

Someone from USPS is walking (or very casually running) 1320 miles from Salt Lake City to deliver my package.