How do you know? It's currently small because it's currently impossible.
> Most non-US residents can do bank transfers as fast as Bitcoin or will be able to Real Soon Now.
I disagree, most non-US residents in the world don't even have bank accounts. Not to mention, the US and Canada are a huge market with a terrible banking system that refuses to modernize.
> So like 5%?
5% is the entire federal VAT in Canada. Would you really say no to saving $100 when buying a new MacBook? Would you just not bother claiming VAT-exempt status for your business because it's a measly 5%?
A fringe here and a fringe there and pretty soon you have a whole robe.