It's the Chinese government subsidising export shipping, not the other way around, I think they bypass the International postal services, in the same way eBay & Amazon do now. I sold a few eBay items to Korea, Japan, and Australia last year, they all went to the same UK address of GSP (Global Shipping Programme) who send bulk consignments to 100 other similar facilities worldwide. Like any large company they get discounted tracked postage in the destination country.
I bought an electronic item via Amazon last years which shipped from California, the tracking showed it sat at an Amazon airport facility for around 10 days, presumably until there were sufficient other items for the bulk consignment.
Ian