After you create a segment, you normally have to wait several days or weeks for it to gain enough members so you can effectively use it for targeting. You can pre-populate the segment to begin targeting the next day.
Pre-population data is derived from ad server logs for the past 30 days of activity in your network. For the most accurate results, you'll want to define your segments using ad units, placements, and key-values that were created at least 30 days beforehand. Pre-population takes the identifiers (cookies, mobile advertising IDs (AdID or IDFA), or PPIDs) from the ad server logs and adds them to the new segment.
As a best practice, you should only pre-populate new segments that have been recently created, typically the same day. Older segments will probably have already started collecting members and, while pre-population won't overwrite these existing memberships, it's redundant.
Pre-populate a new segment
- Create a new audience segment.
- Verify membership and targeting criteria.
- When you're satisfied, click Save and populate.
Pre-populate an existing segment
- Click Inventory
Audience.
- Click the name of the segment that you want to pre-populate and click the Settings tab.
- Verify membership and targeting behavior.
- When you're satisfied, click Save and populate.
Ad Manager will add the identifiers to the segment in about two hours at which point you can target the audience segment. You'll see the higher membership count reflected in audience segment screens in Ad Manager in about 24 hours.
Considerations
- You can't undo the Save and populate action. If you want to make changes to the segment and re-populate it, we recommend that you mark the segment inactive and create a new segment.
- Pre-populating a new audience segment does not immediately grant the ability to forecast on that segment. The forecasting must have enough time to gather impression data from that segment, regardless of whether the segment was pre-populated.
