It's fun how tracking lets you look up the skirt of how all this big shipping companies handle your parcel. Creates a lot of tension and emotional involvement when it was previously invisible a couple decades ago.
I heard that idea of sending everything to central "hubs", then sorting, then the planes leaving with packages bound for their area, came from a college business term paper. He got a "C" on the paper (dumb Prof.)...But Fedex, USPS, UPS etc. thought it was Great.