The reinvention of OOH is accelerating

Opinion

The World Out Of Home Organization’s VP sets the scene and provides the low-down on what to expect from next month’s congress.

The World Out of Home Organization’s Annual Global Congress arrives in London this June at a moment of undeniable momentum—and, more importantly, accelerating structural transformation—for the OOH industry.

Global OOH revenues have grown from $42bn in 2023 to $46.2bn in 2024, with forecasts of $49.8bn in 2025—delivering close to 20% cumulative growth in just two years.

At the same time, digital now accounts for 40% of total OOH revenues and remains the primary driver of expansion globally. In a media landscape where most traditional channels are either flat or declining, OOH stands alone: not only growing but increasing its share of global advertising expenditure.

This growth is not cyclical. It is structural—and it is being driven by three converging dynamics reshaping the global OOH ecosystem: the rapid digitisation of inventory, the advancement of audience measurement and data, and the proliferation of new trading and revenue pathways.

Digitisation is the most visible of these forces

Digital Out-of-Home (DOOH) has expanded to approximately 39% of global OOH revenues, with leading markets such as Australia already reaching around 74% digital penetration and the UK exceeding 66%. These markets provide a clear signal of the industry’s future trajectory: highly digitised OOH environments are increasingly becoming the norm, not the exception.

More importantly, digitisation is transforming the economics and utility of the medium itself. As inventory converts to digital, OOH becomes more flexible, more responsive, and more connected to the broader digital advertising ecosystem. It enables dynamic creative, real-time optimisation, audience responsiveness, and increasingly sophisticated trading models. The medium is evolving from a physical advertising channel into a digitised, data-enabled communications platform.

This structural evolution has accelerated dramatically over recent years through advances in audience measurement and data. Across global markets, we are seeing material improvements in the granularity, sophistication, and interoperability of audience systems. Improved mobility datasets, more sophisticated geospatial modelling, and richer behavioural signals are allowing OOH to deliver increasingly precise and accountable measurement frameworks.

Importantly, these improvements are not occurring in isolation. They are fundamentally changing how OOH is valued within the wider media ecosystem. Historically, OOH’s strength lay in its scale, broadcast reach, and physical presence. Today, it is increasingly defined by its ability to combine those attributes with performance dynamics, measurable audience intelligence, and data-driven accountability.

This progress will be front and centre at the Congress in the “Accelerating Audience Measurement and Standards” breakout session.

Gideon Addy’s presentation of the newly updated WOO Audience Measurement Guidelines marks an important milestone for the global industry. The updated guidelines reflect both technological advancement and increasing international alignment on best-practice measurement principles.

The accompanying panel discussion featuring industry leaders from Australia, New Zealand, the UK, the USA, and Japan will demonstrate how rapidly markets are progressing toward more advanced audience currencies. While methodologies may differ by market maturity and local conditions, the broader direction is unmistakably convergent: toward more standardised, interoperable, and actionable measurement systems that support increasingly sophisticated planning and trading environments.

How inventory is bought and sold

At the same time, the industry is experiencing a parallel transformation in how inventory is bought and sold.

In recent years, we have seen a rapid proliferation of revenue pathways across OOH. Traditional direct sales models, agencies, and specialists now coexist alongside automated trading systems, programmatic platforms, data-driven activation layers, and emerging AI-enabled optimisation tools.

This diversification reflects the changing expectations of advertisers. Brands increasingly expect OOH to operate seamlessly within omnichannel media ecosystems—capable of delivering flexibility, speed, automation, and measurable outcomes comparable to those of digital channels.

Programmatic DOOH illustrates this acceleration clearly.

Global programmatic revenues are forecast to grow from approximately $1.2bn in 2023 to $2.2bn in 2025—an increase of 80% in just two years. While still representing a modest proportion of total OOH revenues, the growth trajectory is significant because it signals a broader structural shift toward automation and scalable digital demand.

These themes will underpin the “Driving Incremental Growth with Adtech” breakout session at the Congress. The release of the WOO Global Programmatic Expenditure Report will provide the industry with its clearest view yet of programmatic’s global scale and momentum.

However, the more important conversation may be philosophical rather than technological: is programmatic itself the future of OOH, or is automation the true driver of scalable growth?

The distinction matters. Programmatic trading often focuses on transaction efficiency and access. Automation, more broadly, encompasses the entire value chain—from planning and audience identification through to activation, optimisation, attribution, and post-campaign analysis. The future growth of OOH will depend less on any single transaction model and more on how effectively the industry integrates these broader automated workflows into everyday media operations.

The panel featuring the industry’s four largest SSPs will examine this issue, exploring what still needs to happen for OOH to unlock its full scalable growth potential.

Econometrics and Marketing Mix Models

Another increasingly influential development is the growing role of econometrics and Marketing Mix Models (MMMs) in shaping global media investment decisions. As advertisers place greater emphasis on measurable business outcomes, OOH’s ability to demonstrate effectiveness within MMM frameworks becomes increasingly important.

Henry Innis from Mutinex will address this directly, examining how MMM adoption is influencing global OOH expenditure patterns. This is a particularly important development because improved measurement and more granular datasets are finally enabling OOH to be represented more accurately in advanced modelling environments. As this continues, OOH is likely to strengthen its position in performance-driven budget allocations that have traditionally been dominated by other channels.

These discussions culminate in one of the Congress’s most important sessions: “The $30bn Unlock: Scaling DOOH Through Global Omni-Channel Demand.”

The premise is compelling. As OOH becomes more digitised, more measurable, and more connected to omnichannel demand systems, its long-term growth ceiling expands significantly. But unlocking that opportunity requires alignment—across markets, standards, technology platforms, and the increasingly complex global value chain.

What becomes increasingly clear is that the industry is no longer experiencing incremental evolution. It is undergoing structural change.

Digitisation is reshaping supply. Audience measurement and data are redefining value. Automation and new trading pathways are reshaping demand. AI and emerging platforms are accelerating operational transformation. Together, these forces are repositioning OOH within the modern media ecosystem in ways that would have seemed improbable only a few years ago.

The significance of this moment should not be underestimated. OOH is no longer simply adapting to the digital era—it is actively benefiting from the same structural forces transforming the wider advertising industry. It remains the only traditional media channel currently achieving this level of sustained structural growth at scale.

The London Congress will not simply reflect this progress—it will help shape what comes next. For delegates attending from around the world, it represents an opportunity to engage directly with the frameworks, technologies, partnerships, and standards that will define the next phase of global OOH growth.

The direction of travel is now unmistakable. The question is no longer whether OOH will transform, but how quickly the industry can scale the opportunity ahead.

Charles Parry-Okeden is the vice president and global lead for audience measurement and data at the World Out Of Home Organization. The World Out of Home Organization (WOO) Annual Congress takes place at the Park Lane Hilton, London, 3-5 June.