Ad mediation platforms sit between a publisher's app and multiple ad networks, running an auction for each impression so the highest-paying available ad wins — but they differ meaningfully in fill rate, reporting depth, and setup complexity.
What to evaluate beyond headline eCPM
Two mediation platforms can report similar average eCPM while differing sharply in fill rate consistency, latency, and the granularity of their reporting dashboards. For most publishers, a platform with slightly lower peak eCPM but more reliable fill and faster support is the better long-term choice.
Integration effort matters more than it looks
Some platforms support a wide range of ad networks out of the box; others require manual adapter integration for anything beyond their own network. That difference can be the deciding factor for a small team without dedicated engineering time for ad ops.