Optimized targeting expansion

Platform

Platforms with 'audience expansion' or 'optimized targeting' features silently deliver impressions outside the submitted geography/audience to hit performance goals, breaking the assumption that delivery equals the requested target.

Detection

Delivered impression geography (from platform reporting) includes cells/areas outside the submitted target set.

Mitigation

Disable expansion/optimization features for geo-experiment cells specifically
Reconcile delivered vs. requested geography every flight and flag material leakage

Affected conversions

H3platform-native IDs
Point+radiusH3