Measurement
The short answer
A US DOOH impression is an audited estimate of exposure opportunities: people passing or present near a screen while your spot plays, calculated under Geopath methodology from location data, circulation counts and visibility research Geopath Ongoing. It is not a served, viewable, one-to-one impression; put that definition next to every CPM you present.
The counting chain
- Circulation: how many people pass the unit, from traffic counts and mobility panels.
- Visibility: what fraction can plausibly see the face, from sightline and eye-tracking research; this is where a billboard differs from a bus shelter.
- Venue multipliers for place-based: venue traffic converted to screen-level exposure estimates; the multiplier is why venue CPMs and roadside CPMs are different units.
- Loop share: your impressions scale with your slots; 1/8 of the loop earns 1/8 of the unit's audience.
Practical rule: ask for the per-unit audited weekly impressions in the quote Geopath Ongoing, then do budget / impressions x 1,000 yourself and compare to the published band AdQuick 2026.
Attribution, with its limits attached
- Footfall studies: mobile panels matched from screen exposure zones to store visits; directional, panel-based, vendor-run. Demand the methodology page, not just the lift number.
- Brand lift: exposed-vs-control surveys; the standard for awareness claims, sensitive to sample quality (what studies show).
- Branded search and direct traffic by flight geography: the cheapest honest signal, built into the $25k test design.
- What does not exist: click-level attribution. A plan promising DOOH conversions tracked like paid search is misdescribing the medium (the honest comparison).
In pDOOH reporting
Programmatic reports arrive impression-formatted like display, but the underlying unit is still the multiplied exposure estimate; the DSP row and the billboard row are different animals wearing the same column header (the pipes). Play-level verification comes from CMS proof-of-play logs, the naming ancestor of our source register. Numbers to hang it on: rate board, planner.