Why Scale and Geography Still Define DOOH Value
The programmatic DOOH market crossed an inflection in 2025. According to eMarketer's 2025 DOOH forecast, US programmatic DOOH spend reached $1.27 billion — a 34% year-over-year increase. Yet most of that growth concentrated in premium large-format inventory in ten metropolitan markets. The long-tail question — what happens outside those ten markets — has gone largely unanswered because no operator had both the measurement infrastructure and the geographic footprint to report on it credibly.
The Trillboards network sits squarely in that gap. As of May 2026, 8,715 active screens operate across 22 countries, with 2,054 distinct US city markets covered. This is not projected reach; it is observed telemetry. Every screen in this dataset transmitted at least one heartbeat event during the observation window (2026-01-01 through 2026-05-11). Screens that missed two consecutive 30-second heartbeat windows were flagged inactive and excluded from counts.
Geographic Distribution
The United States represents the largest single-country share of the network, consistent with the maturity of US programmatic DOOH infrastructure and the density of DSP integrations with US-specific deal IDs. International screens — spanning Canada, the United Kingdom, Australia, and 18 additional countries across Europe, Latin America, and Asia-Pacific — account for a meaningful minority of total screens but show materially different fill patterns (see Chapter 2: Fill Rates).
US City Coverage — The 2,054 Market Story
Industry-standard DOOH network reporting typically lists Designated Market Areas (DMAs). The Trillboards network covers 2,054 discrete US cities, many of which fall outside the top-50 DMA list entirely. This matters for two reasons. First, brands running regional campaigns cannot ignore the long-tail: a regional grocery chain or healthcare system may have zero presence in a top-10 DMA but saturate a mid-market. Second, CPM benchmarks in non-top-50 cities systematically underperform the top-10 average, presenting a yield optimization opportunity for venue owners that historically lacked the scale to attract programmatic demand.
Venue Category Breakdown — 38 Categories
The IAB DOOH venue taxonomy organizes screens by physical location type. The Trillboards classification system maps to the OAAA's venue-type framework with 38 distinct categories active as of Q1 2026.
What Changed Since 2025
Three structural shifts stand out in the year-over-year comparison. First, fitness and recreation venues increased their share of the network by 5 percentage points — the largest category-level change in the dataset. Post-pandemic return-to-gym behavior coincided with venue operators seeking new revenue streams; the DOOH model, which requires no capital expenditure from the venue, accelerated deployment in this category.
Second, education and workplace venues nearly doubled their share (from roughly 3% in 2025 to 6% in Q1 2026). Corporate office return-to-work mandates in Q4 2025 brought lobby and common-area screens back into active ad-serving inventory after an extended period of reduced occupancy and deprioritized programmatic configuration.
Third, international screen growth outpaced domestic growth on a percentage basis, though the absolute numbers remain skewed to the US. Canada and Australia each added more than 200 net new screens during the observation window, driven by multi-venue chains activating existing hardware.
What to Expect in 2027
Based on network trajectory and conversations with venue operators, healthcare and medical waiting room inventory is likely to emerge as the highest-growth category in 2027. Regulatory clarity in the US around healthcare DOOH — specifically, OTC pharma creative running in waiting-room contexts without requiring HCP-specific targeting — has opened demand that was previously blocked at the deal-ID level. The IAB's 2025 DOOH standards update (see the OAAA OOH Primer) explicitly addresses this use case.
Transit inventory faces a different trajectory: screen density is high but fill rates in this category are structurally lower (see Chapter 2), driven by shorter dwell times and the absence of real-time audience measurement. Sensing infrastructure that can confirm person-count and attention levels — not just location — is the prerequisite for transit CPM premiums to close on the gap with waiting-room and fitness inventory.
Implications for Advertisers
A 2,054-city footprint means national campaigns can achieve genuine geographic completeness without separate direct deals in each market. The programmatic waterfall handles it — provided the DSP seat has activated the relevant supply path. The practical implication: buyers should audit their exclusion lists for non-top-50 cities, which are frequently flagged as "unverified" in legacy OOH measurement systems despite carrying the same beacon and telemetry signals as Tier 1 inventory.
Implications for Venue Owners
Network size creates programmatic gravity. A venue operating one or two screens in isolation cannot attract the DSP attention that a 50-screen chain receives automatically. The data shows that venues that joined the network with 3+ screens saw fill rates 18% higher than single-screen additions in the first 90 days — a direct consequence of minimum-impression thresholds in most DSP floor-price configurations.
External References
- eMarketer (2025). US Digital Out-of-Home Advertising Forecast. Insider Intelligence.
- IAB (2025). Digital Out-of-Home Advertising Standards: Venue Taxonomy v2.1. Interactive Advertising Bureau.
- OAAA (2025). Out of Home Advertising Primer. Outdoor Advertising Association of America.
- PQ Media (2026). Global Digital Out-of-Home Media Forecast 2026–2030. PQ Media LLC.