I love that part of the story where they decided to use only USPS Flat Rate boxes. And within the first year the PO was having to send a special truck, just to their address.
I ordered one of their "Bundles" one time. Basically it was about 3000 bullets that totaled right up to the 70lb USPPS weight limit. I had it delivered to my work address as a joke. We had this 90lb secretary that delivered the mail every afternoon. One day I got a call, "Can you come down here, there's a box for you that I can't lift !"