Third-Party Ad Serving (3PAS)

Serving and tracking ads through an advertiser-side ad server, such as Campaign Manager 360, separate from the publisher's ad server.

By Brandon MinaCEO, BrandPilot AIUpdated November 2026

Short answer

Third-party ad serving (3PAS) is the practice of serving and tracking ads through an advertiser-side ad server, such as Campaign Manager 360, separate from the publisher's ad server. It gives advertisers centralized control of creatives, consistent cross-publisher measurement, and an independent count of impressions and clicks for comparison with publisher reports.