Yes! You're exactly right... dual taxation is on a per-country basis. It depends entirely on the agreements each individual country has... which means the dual taxation situation isn't because of taxation technology but more political agreements. I believe it's an easy solution as long as everyone agrees to fix it.

So GST & VAT are technically taxes on both corporations and citizens. In Australia, a company purchases a widget and they pay GST on that widget. If they can prove that they sold that widget to a customer, they get that GST back. If they can prove they transformed or added that widget to a bigger product and sold that bigger product, then they get the original GST back.

The end result is that everyone is paying GST on everything, but companies can claim a lot of GST back. The problem is though, if an Australian company purchases Facebook advertisements, then they don't pay GST - because Facebook is located in Ireland... so we really need some sort of global flat rate GST/VAT so that corporations can't just move their locations to minimize their taxation requirements.