GPGAMES.de is a great site with many files on their servers, with a high file traffic.
It costs a lot of money to have good servers that will make it possible that you can download the newest addons for grand prix 4.
Think amazon is a sponsor of this site - its a little bit cheeper for webmaster to have this servers and because amazon is a sponsor they will get a pop up so that users go to their site.
If the window opens you can simple close it - it takes a second not more. So i think its no problem.
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