Country mix diagnosis
Why country mix can make blended eCPM look worse
Blended eCPM can drop even when your top-country eCPM is stable. If more impressions shift toward lower-eCPM countries, the average can look worse without a global demand collapse.
What blended eCPM hides
Blended eCPM compresses every country, placement, format, and ad source into one average. That makes it useful as a headline metric but risky as a diagnosis.
Why country mix matters
A larger share of impressions from lower-eCPM countries can pull the average down even if Tier 1 eCPM is unchanged. The revenue problem may be traffic mix, not demand.
Compare country-level eCPM before changing global settings
Changing global floors or mediation rules before splitting by country can make the wrong segment worse. First compare eCPM, impressions, and revenue contribution by GEO.
Separate Tier 1 trends from blended trends
If US, UK, CA, or other top GEOs are stable but blended eCPM is lower, inspect whether lower-value GEOs gained impression share.
What to check before changing mediation
Review UA campaigns, organic traffic sources, placement exposure by region, and ad source contribution. A source issue and a country-mix issue can look similar in the blended average.
Practical checklist
- Compare impressions share by country.
- Compare revenue contribution by country.
- Check top GEOs separately.
- Compare placement exposure by region.
- Review UA campaigns and organic traffic sources.
- Do not change global mediation settings before separating country mix from source performance.
How to read it
Common interpretation
If country-level eCPM is stable but lower-eCPM GEOs gained share, the blended eCPM drop is probably a mix issue. If the same country and placement dropped across multiple sources, then demand or source pricing becomes more likely.