Amazon affiliate traffic outside us

Hi,

I have a few new amazon affiliate sites, and I got nice amounts of US traffic, but also a lot of uk\ca\au traffic as well.

Will I get a commission for any sale made outside of US? meaning by the traffic coming from those 3 countries?

And from your own personal experience, do those countries has buying power as well? compared to the US of course.

Thanks

still looking for help - thx