I didn't have a great experience with online shopping across the world but I can tell you the following :

When I ordered within the EU, I didn't have to pay VAT and the package was dropped directly in my postal box, so I presume that the seller paid VAT in his country (in this case it was Germany).

When I ordered outside the EU, I had to go to the customs representative at the postal office and declare the value of the package (as it didn't have an invoice, which I received by e-mail), and pay the VAT at the declared value.

So I presume that when you will send the packages, if the country of destination is within the EU, you will have to pay the VAT in Germany (at the VAT of the buyer's country starting from January 2015 if I recall) and the buyer will receive the package in his postal box ; if the country of destination is outside the EU then you won't pay VAT in Germany and the buyer will have to go to customs and declare the value (or present the invoice) and pay VAT there.

This is simply my experience and my understanding of how things work.