Why DOOH Is Stealing Ad Dollars From Linear TV - And What It Needs to Keep Winning.

The Money Isn't Coming From Where You Think

For years, the narrative around Digital Out‑of‑Home went like this: static billboards are dying, digital screens are replacing them, and the growth is simply analog dollars converting to digital format.

But that oversimplified story doesn’t hold up under scrutiny. DOOH isn’t just digitizing outdoor ads — it’s growing as a distinct media category. In fact, analysts project that global DOOH advertising revenues will continue to expand significantly through the decade, with digital formats accounting for an increasing share of out‑of‑home spend (for example, DOOH is forecast to represent nearly 42 % of OOH ad revenues worldwide by 2025 and grow toward $30 billion in annual spend by 2029).

In a recent DPAA session, one measurement firm dropped a data point that reshapes everything: DOOH isn’t growing because static out‑of‑home is shrinking. In fact, those two trends are largely disconnected. Static is losing market share, yes, but that money isn’t simply migrating to digital screens, it’s evaporating or shifting to other channels entirely.

The real story? DOOH growth is coming from linear TV. And to a smaller but notable extent, from Connected TV (CTV) — a format that is itself growing rapidly, with some reports showing CTV viewership and ad impressions increasing markedly year‑over‑year while linear TV remains flat, as stated by TV Tech.

This isn’t a cannibalization story within out‑of‑home. It’s a channel‑shift story that positions DOOH as the emerging “third screen” (alongside CTV) in a post‑linear, AI‑disrupted media landscape. But capturing this wave requires DOOH sellers to solve a translation problem they’ve mostly ignored.

The "Spot" Language Bridge

When you watched broadcast TV (over antenna, cable, or satellite) shows contained structured ad breaks: specific time allotments with defined numbers of spots (individual commercial slots). Media buyers purchased these spots based on reach, daypart, and audience composition. The unit of currency was time‑based availability within a programming context, not impressions served to cookies or devices.

Most DOOH video inventory sells using this exact same “spot” framework. A digital screen at a gas station runs a loop with defined ad breaks. Buyers purchase spots within that loop. The language is identical to linear TV.

This is not accidental. It’s strategic.

Linear TV buyers are comfortable with spots. They’re uncomfortable with impression‑based digital buying. DOOH video speaks their native language while offering the targeting and measurement they’ve been promised for decades.

The speculation is that this linguistic familiarity is accelerating the transition. Linear is collapsing. That money must go somewhere. DOOH offers the closest operational analog to what TV buyers already know.

The AI Disruption Creating DOOH’s Moment

There’s a second, larger force at work. One that’s making DOOH and CTV the most resilient advertising channels in an otherwise volatile landscape.

AI is collapsing online publisher inventory.

Consider the behavioral shift: when you had a question like “what’s the best car?”, you used to Google it, click through to Edmunds, Kelley Blue Book, or AutoTrader, read their content, and return multiple times. Those publishers built businesses around capturing that intent‑driven traffic and selling premium placements to brands.

But today, you ask an AI assistant and you get a synthesized, personalized answer. You may never visit a single publisher’s site. The inventory — the webpage, the article, the engagement, simply disappears. An analysis by AI SEO Journal, shows traditional search referrals have declined sharply as AI summaries displace link‑based discovery, with some data indicating search traffic to publishers has dropped by as much as 33 % year over year.

The “flood the channels” strategy (buying presence where your audience congregates) breaks when AI intermediates the relationship. The one area AI cannot disintermediate? Physical presence.

People still watch screens (especially CTV), and people still move through physical environments: at gas pumps, transit hubs, airports, and city streets. These are contexts where presence cannot be summarized away. The screen is there. The audience is there. The brand can guarantee visibility in a way no algorithmic answer can replicate.

What DOOH Needs to Harness This Momentum

The opportunity is massive. The infrastructure to capture it? Mostly inadequate.

Here are the technical and operational requirements for DOOH to absorb linear TV’s migrating billions:

1. Normalize Inventory to Impression‑Based Metrics

TV buyers may be comfortable with “spots,” but CFOs and procurement teams still require impression‑based accountability. The challenge: can you translate 100 screens into guaranteed impressions?

Most DOOH sellers cannot answer this confidently. They sell on screens, units, or share‑of‑voice, then extrapolate what that means in reach. This creates friction in the buying process and limits access to performance‑marketing budgets.

Infrastructure requirement: Inventory management systems that model availability across complex location grids, calculate realistic impression delivery based on traffic and dwell‑time data, and expose this through APIs that plug into agency planning tools.

2. Automate Media Planning at Scale

Linear TV planning is complex but standardized. DOOH planning is complex and bespoke — every network has unique location attributes, audience data structures, and availability logic.

The current state at many DOOH operators: planners download location lists, manipulate them in Excel, manually check availability against multiple systems, re‑upload to ad servers or CMS platforms, and iterate when guarantees aren’t met. Hours per plan. High error rates. Revenue lost to overbooking “buffers.”

GSTV operated this way until recently, managing 30,000+ locations through spreadsheets, overbooking their inventory just to guarantee delivery, losing revenue they could have sold at premium rates.

Infrastructure requirement: Smart media planning tools that ingest location and audience data, apply allocation rules (even distribution across DMAs, budget‑weighted optimization, impression targets), and generate executable plans in minutes rather than hours.

3. Bridge Ad Serving and Content Management

Here’s a DOOH‑specific complexity that digital media veterans often miss: most DOOH inventory doesn’t run through traditional ad servers.

In online publishing, systems like GAM or Freewheel handle delivery, targeting, and measurement. In DOOH, many networks run through CMS platforms built for editorial content, not advertising. These systems often lack API connectivity, requiring “swivel chair” manual workflows where someone transfers data between systems by hand.

The ad servers that do exist in DOOH are specialized for audience data and location targeting, but may not handle planning and workflow automation that media operations require.

Infrastructure requirement: Integration layers that connect planning systems to both ad servers and CMS platforms, with API flexibility for the latter and data enrichment for the former.

4. Unify Multi‑Format Operations 

For legacy out‑of‑home giants, the complexity compounds. They sell static bulletins, digital loops, and transit inventory with entirely different workflows.

Many run on proprietary systems built decades ago that weren’t designed for digital inventory or API‑centric operations. These CTOs face architectural decisions that will define competitive position for the next decade: rip‑and‑replace for a modern unified platform, or best‑of‑breed integration that modernizes incrementally?

Infrastructure requirement: Flexible inventory models that can handle units, impressions, spots, and time‑based calendar sales  within a single operational framework: without requiring monolithic, unmaintainable systems.

The Competitive Window

DOOH is experiencing a rare confluence: demand tailwinds from linear decline and AI disruption, paired with supply‑side infrastructure gaps that create first‑mover advantages.

The sellers who solve the translation problem and who can speak TV buyer language while delivering digital targeting and measurement precision, will capture a disproportionate share of the migrating billions.

The sellers who don’t? They’ll remain stuck in spreadsheet planning, manual workflows, and “buffer” inventory management that lights revenue on fire.

The tools are doing one thing: making it easier for sales teams to sell more, sell quicker, sell more effectively. In a market where linear TV’s collapse is creating immediate budget availability, that operational speed isn’t efficiency, it’s competitive survival.

Key Takeaways 

DOOH isn’t just digital billboards. It’s becoming the physical anchor of brand visibility in an era where online presence is increasingly intermediated by AI and linear TV is structurally declining.

But realizing this potential requires infrastructure investments that many operators have deferred. The Companies making those investments now (in inventory visibility, workflow automation, and metric normalization) aren’t just optimizing operations.

They’re positioning to absorb the largest channel shift in advertising since the rise of mobile.

The money is moving. The question is whether DOOH technology can move fast enough to catch it.