Mixed-provenance channel bundle

advertising

A multi-channel activation (e.g. CTV + DOOH + mobile) mixes location provenances of very different quality; because any channel's exposure puts a household in the treatment arm, the bundle's assignment integrity is set by the worst-resolving channel, not the average — one contaminated stream contaminates the arm.

Detection

Channel mix spans provenance classes (physical, address_matched, ip_inferred) while the experiment unit was chosen for the best class.

Mitigation

Take the coarsest floor across activated channels as the assignment unit
Record per-channel provenance in the campaign record so the floor is computable at design time
Point-resolved channels (physical screens) keep their precision for delivery and audience work — only the assignment unit degrades

Affected conversions

Point → H3 exact
IP lookup → H3 (probabilistic crosswalk) approximate
H3 → platform-native IDs approximate