ok that's good. So if I understand it , I can register in all aff programms from amazon all over the world?

yes and no, look where your traffic is coming from and sign up with that country some people have reported amazon wont let them sign up with to many

I understand. But that was just an example :D. I am not going to sign in every amazon affiliate programm :)

You can add the Geniuslink plugin which will redirect your visitors to the right country with just 1 link.
Let's say I am in Germany I will be automatically redirected to Amazon Germany, I am for the UK , same link will bring me to Amazon UK.
You need to sign up for all Amazon programs though ( or the countries you get the most visitors from).

Another thing about Amazon US is that you can only get paid by gift cards ( maybe other methods) and not in money if you live in Germany.

Hi oh ok I dnt know this plugin. Will look at it :) What do you mean with Gift Cards? So if a do an English site, I wont get money, just gift cards when I sell something? that's not good :(