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DOOH GlossaryDOOH Fundamentals

DOOH (Digital Out-of-Home)

DOOH is digital screen-based advertising in public and shared spaces — bars, gyms, retail, transit — bought and measured the same way as web or CTV.

Digital out-of-home (DOOH) advertising is any commercial message delivered on a digital screen in a public or shared space — a bar TV showing pre-roll between innings, a gym lobby running a 15-second slate, a convenience-store cooler with a strip display. The defining trait is that the audience is sharing the screen, which means impressions are multi-viewer by definition (one playout, N pairs of eyeballs) and the measurement model has to account for that.

Two things separate modern DOOH from the dumb-billboard image people still carry. First, the screens are addressable: a server decides what plays next, often in real time, based on time of day, weather, audience composition, or a programmatic auction. Second, the screens emit telemetry — at minimum a proof-of-play log; on Trillboards screens, a full audience signal stack including cohort composition and attire archetype.

Globally, DOOH crossed $20 B in 2026 and is the fastest-growing OOH segment by a wide margin. The IAB and OAAA align on a four-tier venue taxonomy (Roadside, Place-Based, Point-of-Sale, Transit), with deeper subcategories for buyer targeting. The buying motion is converging on programmatic: programmatic DOOH ran ~30% of US digital OOH spend in 2026, and OpenRTB 2.6 added a "dooh" object so DSPs can bid on placements with the same protocol they use for video.

Authoritative reference

OAAA — Digital Out-of-Home

See also

Place-Based Media
Advertising on screens located inside a specific kind of venue — bar, gym, salon, doctor's office — where the audience self-selects by being there.
Programmatic DOOH (pDOOH)
DOOH inventory bought through real-time auctions instead of insertion orders — the same DSP/SSP plumbing that runs web and CTV.
Ad Slot
A single time-window on a screen where one ad plays — typically 10-30 seconds in DOOH, sold as one impression-bearing unit.
OOH (Out-of-Home)
The umbrella category for all advertising outside the home — billboards, transit, posters, plus the digital subcategory DOOH.

Reference docs

Building against Trillboards?

Our developer reference covers the DSP API, partner SDK, proof-of-play verification, and the sensing pipeline that powers buyer-grade audience signals.

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