International postal agreements cap the cost to China Post for the final delivery of mail artificially low and USPS has to absorb the actual final delivery cost

International postal agreements cap the cost to China Post for the final delivery of mail artificially low and USPS has to absorb the actual final delivery cost. Because of that artificial cap and China Post's cost of mailing, the shipper bears a very low cost. Probably still losing money mind you but that loss is in effect heavily subsidized. Airmail costs for a button would be 6 RMB or $0.91 per china post's web site for a letter in the 3rd group (US, Europe, Canada, OZ, NZ). Surface mail cost for the same letter would be 4 RMB or $0.61. That's cost if you walk up to the post office. I don't really have the patience to try and sort out the discounts that might apply to volume shippers. I assume they have the whole line of discounts for electronic stamps, large volume shippers and pre-sorted mail, amongst others.