If they sell to the public, probably quite a few. When the sender uses a parcel service the recipient gets to pay the fee for customs brokerage, but with the post it's included.

Commercial recipients know about brokerage fees and can estimate how much the surcharge will be, but Joe Random has no idea and will complain.

Our company is one. About 20% of our sales are outside the US. We ship international shipments via USPS exclusively because it has always been the best value.

There is a market where people buy from us based companies, the items are made elsewhere but people are more comfortable buying from a us brand