Sure, the USPS does more than deliver grocery store spam -- but not much more. A plurality of mail sent via USPS is spam, and the majority of that mail remains

Sure, the USPS does more than deliver grocery store spam -- but not much more. A plurality of mail sent via USPS is spam, and the majority of that mail remains unopened (if it's not a leaflet). The main parcel shipped by the USPS is physical waste.