I'm talking from the perspective of the seller and of course I can only talk about our experience. Again, shoes (high priced too) are probably very different from cheap USB connectors. And having to ship a pair of 200,- € shoes back and forth from europe to the USA until the customers found the correct size is not worth the effort in our opinion. It's hard to find a proper return service - you can't leave that task to the customer; if proper export documents are missing we have to collect the return package from the customs. It's a mess.

And if you ship larger amounts you have to register the export with the customs office, which is another complicated process, filling endless forms in some mandatory Java applet system.

Amazon getting rid of all of this for a reasonable price would be very welcome.