Based on your update in the comments
I'm thinking about using it on my blog, so not really programming-related (hence my question here). The question itself is if I should use the .com or .co.uk amazon site (as I'm located in Europe but most of my visitors are US-based)
I'd say http://webmasters.stackexchange.com/ -- webapps is end user focused, not really focused on people who manage a website and make decisions like this about content that is being posted to the website.
It wouldn't be terrible on webapps, it could work there, but the "webmaster" vs. "end user" distinction is what matters here. So I suspect you'll get much, much better answers from "people who run websites" than "people who use GMail and Facebook".
And in the future, you can always check
http://stackexchange.com/sites to see what sites we have, and what the audience is for each one.