Symptom
The distortion lives in campaign-level CPA reporting that aggregates every targeted geography into a single average — making regional performance variance invisible without deliberate location segmentation.
Cause
A portion of spend flows into regions where the acquisition cost structure is structurally above the program average due to auction-driven distribution without location-level efficiency constraints.
Impact
Teams optimize toward blended CPA benchmarks and apply campaign-level changes to a problem that is geographically concentrated — missing the recoverable efficiency that location bid adjustments can unlock.