An unfilled impression represents an ad request that did not return a line item and means that no line item was eligible to serve. You might think of unfilled impressions as a warning; they represent lost revenue that could be captured with paying campaigns, and should be corrected as soon as possible.
Find where unfilled impressions are serving
- Sign in to Google Ad Manager.
- Click Reporting Reports.
- Click New report. The "Historical" report type is selected by default.
- Click and select a date range.
- Include inventory dimensions:
- Click Inventory Ad unit (all levels) to view unfilled impressions for ad units of all levels.
- Click Inventory Requested ad sizes to view unfilled impressions by ad request size.
- Select Unfilled impressions from the "Total" group in the "Metrics" section.
- Click Run.
Review the report
Based on the ad unit and requested sizes in your report, make an educated guess about the location of the tags serving the most unfilled impressions. Use the Ad Manager delivery tools to determine why line items might not be delivering. If there are no eligible line items to serve to the ad slots in question, you've found where unfilled impressions are serving. To stop unfilled impressions, either eliminate the ad slot from the webpage or traffic remnant or house inventory to the criteria in the tag.
You can proactively monitor unfilled impressions in your network by saving and scheduling the report above.