It's cheaper to ship 10,000 items in a single container, than to ship each one separately, which is why mail carriers bundle items together (in bags, vans, containers, etc) instead of handling them separately all the way.
Domestic mail is like sending separate items, which get bundled together, then un-bundled again to deliver them to their final destination. All these steps happen at domestic wages, and at best with medium volumes. If there are not enough items to fill a container, it's still getting sent some other (more expensive) way.
Items from China get bundled by lower wage workers, the bundles are sent by lowest priority freight (usually a 7-45 day delay), bundles are only sent when fully filled in order to minimize costs per item, and sorted to minimize un-bundling costs.
This won't change no matter what, it's just economy of scale.
There are other factors like the reduced shipping costs for China set by the UN, or the fact that some will ship items at a loss just to convert Yuan to USD through Hong Kong, but ultimately the production vs. consumption imbalance is what decides most of this.
Basically has to be right? Even if the shipping labels were completely standardized, you still have to deal with irregular package dimensions, composition, and label locations. The sort of stuff that robots aren't so good at.
I don't see how poly bags offer any weight advantage over an envelope. The advantage they have is durability: paper envelopes get easily ripped open, whereas poly bags are nearly indestructible for about the same weight and size. I've also noticed that many shippers now print their mailing/customs label directly onto the poly bags, so that probably makes the shipping process faster and more automated.
This ignores the actual reason, which is that USPS charges less for China->US movement than domestic movement even after bundling like Amazon does at the warehouse.
Exactly this. It has nothing to do with the boat cost or economies of scale because once it arrives it has to still go that last mile - or last hundred miles within the U.S. the same as any package.
Domestic mail is like sending separate items, which get bundled together, then un-bundled again to deliver them to their final destination. All these steps happen at domestic wages, and at best with medium volumes. If there are not enough items to fill a container, it's still getting sent some other (more expensive) way.
Items from China get bundled by lower wage workers, the bundles are sent by lowest priority freight (usually a 7-45 day delay), bundles are only sent when fully filled in order to minimize costs per item, and sorted to minimize un-bundling costs.
This won't change no matter what, it's just economy of scale.
There are other factors like the reduced shipping costs for China set by the UN, or the fact that some will ship items at a loss just to convert Yuan to USD through Hong Kong, but ultimately the production vs. consumption imbalance is what decides most of this.