You can exclude an entire set of topics from showing your ads on Google's Display network. This strategy can help you get more out of display by blocking all irrelevant websites related to certain subjects at once.
Review the campaign's performance and individual display placements where your ads have appeared. If you notice that certain types of websites, such as gaming websites, show your ads but are not relevant to your audience, consider excluding gaming topics.
To exclude topics, perform the following steps: