You can exclude placements that do not suit your ad campaign for some reason. For example, if they aren’t appropriate for the brand or are not profitable.
A company that sells children’s furniture. The company notices that some of their ads are showing on automatic placements that are relevant to the topic but not children oriented. You can exclude such placements from an ad group.
It is possible to exclude placements from the Display Network tab:
1. Go to your Display Campaigns and click Placements
2. Select Exclusions
3. Click the pencil icon
4. Click either the “Add placement exclusion” or “Use placement exclusion list”.
5. Choose where to exclude from e.g. account, ad group, and campaign
6. Type a placement in the box, entering just one placement per line. You can exclude up to 10,000 placements per campaign. Note: You don't need to exclude a placement if it's located outside the target region for your ad. No matter where a site is located, your ad will be shown only to visitors located in the regions you've targeted.
7. Click Close and then Save.