You're working with a beverage client on a new campaign. After reviewing a report in Campaign Manager 360, you notice that the default ads are running more often than the new campaign-assigned ads.What could be the cause of this issue?

When default ads serve more frequently than intended, it is typically because geo and language targeting limits the serving of preferred ad creatives, causing the system to fallback to the default ad when a user does not meet those specific criteria. In the Campaign Manager 360 ad-serving logic, if a placement's primary ads have restrictive targeting—such as specific geographic regions or language settings—any user outside of those parameters will be ineligible to see the campaign-assigned ads; since a placement must always serve an impression if called, the ad server defaults to the "catch-all" default ad to ensure the inventory isn't wasted. Unlike priority settings or creative variety which usually dictate which specific ad serves among eligible options, strict targeting filters directly disqualify ads, making the default ad the only viable technical solution for the impression.