Case Study: MediaMath achieves incremental reach to high-value users with OpenX Bidder

MediaMath - Customer Case Study

OpenX and MediaMath partnered to test whether header bidding — typically a publisher-side tool — actually increases buyer reach, especially to high-value users. They examined a sample of OpenX exchange requests and matched user data to determine if header bidding exposed impressions and audiences that tag-based exchange integrations missed.

Using OpenX Bidder with MediaMath’s TerminalOne, the test mapped a subset of high-value users across 900M ad requests and found clear incremental reach: OpenX Bidder delivered 24% more matched users and 16% more high-value users than tag-based integrations, and added one new user for every 24 opportunities. The result: buyers should include header-bidding enabled publishers (accessible via TerminalOne) to maximize reach and more effectively access valuable audiences.

MediaMath