I run a handful of small content sites — Perl School, Readabooker, Mercurial Albums, and a few others. They're all different niches, but they share one thing in common: they link to products on Amazon, and those links carry my associates tag.
If you've ever tried to do this properly, you already know the problem. Amazon isn't one store, it's dozens — amazon.com, amazon.co.uk, amazon.de, amazon.fr, amazon.co.jp, and so on — each with its own catalogue, its own currency, and its own associates program. A link to amazon.com is nearly useless to someone in Germany. It won't reliably resolve to the local listing, and even when it does, you don't get credited for the sale because you're not in the German associates program for that link.
So every site owner with an international audience ends up picking one of two bad options:
Pick one store and eat the loss. Link everything to amazon.com, or amazon.co.uk, or wherever your own associates account lives, and accept that a chunk of your visitors will either not click through or will click through and generate no commission for you.
Maintain a link for every store. I had a Perl program that would generate a button or a link for a given ASIN for every Amazon site I thought I needed to cover. This scales terribly once you're running more than one site; it looks horrible on the website; and it's exactly the kind of tedious, error-prone busywork I wanted off my plate.
