Also the volume of material to be delivered is phenomenal. There's a completely mercenary reason to try to deliver everything you can - storing things costs money and you aren't in the storage business.

This is why I don't pay merchants for any sort of expedited delivery. I live in a major port city. Any self-respecting delivery business has a depot in this city - some have several, which means any products destined for me aren't going via the far end of the country, or to a city I've never visited, they are definitely coming here ASAP.

And once they are in that depot they are taking up space that the company pays for. The sooner my package is on a truck and delivered, the less it cost to store it, and the more profit they keep. Now, if I paid for the most expedited delivery, perhaps my package would make it onto the very first truck and I'd be the first stop and I'd be woken by an anxious delivery worker buzzing me. If I ever need something for 0800 the next day I'll keep that in mind. But if I'm a little bit more patient the next truck, or the one after, will have some space and my package goes in that truck. Maybe if I'm unlucky the product arrives at midday. Good enough.