Visitors tracked, goal to external website isn´t

I made a very basic, one page affiliate website. I installed Piwik, put the provided script before the tag and my visits are tracked, I see myself tracked in real-time! So far so good. Then I added a goal:

Goal is triggered when visitors -> click on a link to an external website -> contains -> extwebsite.com (this is precisely how i added it, like the amazon example provided.)

…nothing. No clicks are recorded. I tried for 2 days, but my clicks are not tracked. The website hasn’t been indexed yet so I am the only visitor.

Do I miss something? Add a class to the link? It is just a normal html link go to extwebsite thats all.