Whenever you are running a display campaign you should carefully monitor on which placements your ads are shown. This shortcut will show you how to analyse placement reports in Google AdWords. Also make sure to check out the other (more advanced) shortcut to analyse placement performance using Google Analytics.
Click on a display campaign -> Display Network -> Placements
This overview shows you all of the domains where your ads were shown. For a more detailed report at the URL level, click on “See Details” -> All.
The report below shows the exact URLs where ads where shown. You can download the report and exclude domains and URLs based on performance. You can also create separate campaign or ad groups targeting the best performing URLs.