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ROI, ROAS, and ROMI: What is the difference, and which one should you use?

When allocating budgets across OOH, DOOH, search, social, TV, and retail, three acronyms quickly become central: ROI, ROAS, and ROMI. They may sound similar, but they measure different things, and your choice of metric can determine whether out-of-home advertising is viewed as a cost or as one of the most powerful engines in your media mix.

Below, we break down the differences, how to calculate them, and when each metric is most useful in an OOH/DOOH-driven media strategy.

1. ROI: The big picture of the business

What is it?

Return on Investment (ROI) measures the total return on an investment: how much profit you get back in relation to what you have invested. It is used widely in general business and finance, not just in marketing.

• Formula: (Profit – Cost) / Cost

How does it relate to OOH/DOOH?

When looking at ROI, you want to see how the entire marketing budget contributes to results, not just the “last click” from a digital ad. OOH often plays a larger role than “last-click” models reveal:

• OOH builds mental availability and demand, which is subsequently captured via search, programmatic, social, and in-store.

• Studies from the OAAA show that reallocating even a small portion of an existing budget to OOH can result in clear gains in both sales ROI and brand metrics without increasing total spend.

When to use it:

• To evaluate the entire marketing effort from a business perspective.

• When communicating with a CFO or management to show how marketing budgets impact results and profitability.

• When optimizing the media mix at the portfolio level (e.g., how much to spend on OOH/DOOH compared to other channels).

2. ROAS: Sharpness at the channel level

What is it?

Return on Ad Spend (ROAS) focuses on revenue per ad dollar, usually within a specific channel or campaign. It is the most common metric in digital marketing.

• Formula: Revenue from campaign / Ad spend

• Note: ROAS does not account for costs outside of the media buy (e.g., staff, tech, agency fees).

How does it relate to OOH/DOOH?

OOH and DOOH often influence the ROAS of other channels more than their own “on-paper” channel ROAS:

• OAAA analysis shows that when a portion of TV and digital budgets is shifted to OOH, both ROAS and brand metrics rise, as campaigns reach an optimal efficiency level rather than over-investing in the same saturated digital surfaces.

• Analysts often find that OOH-exposed areas show higher search and social ROAS, simply because more people are already aware of the brand when they encounter a digital ad later.

When to use it:

• To compare how different channels perform in pure revenue per media dollar.

• When optimizing tactical investments within DOOH networks, paid search, or social.

• To prove the “priming effect”: compare ROAS in areas where an OOH campaign is active versus control areas without OOH support.

3. ROMI: The Marketing Manager’s favorite metric

What is it?

Return on Marketing Investment (ROMI) is essentially the ROI of marketing. The focus is on the profit or contribution generated by marketing initiatives after deducting marketing costs.

• Formula: (Profit from marketing – Marketing cost) / Marketing cost

• ROMI is often used alongside Marketing Mix Models (MMM) and incremental testing to compare everything from brand campaigns in OOH to “always-on” search.

How does it relate to OOH/DOOH?

OOH/DOOH provides both short-term and long-term contributions:

• Short-term: Campaign-driven sales lifts in exposed areas.

• Long-term: Stronger brand equity, higher preference, and higher conversion rates across all channels.

• To capture the true contribution of OOH, you need the ROMI perspective, where both brand impact and sales are accounted for. International studies (e.g., Omnicom/Benchmarketing) suggest that an optimized OOH share in the media mix provides superior ROMI precisely because the effect spills over into other channels.

When to use it:

• To prioritize major strategic initiatives: e.g., “national OOH launch” vs. “increased always-on budget in social.”

• When building business cases to increase the OOH/DOOH share in the mix.

• To balance short-term performance with long-term brand building.

Comparison Table: Which one should you choose?

Conclusion: Choose the metric based on the decision

• Use ROAS when optimizing tactical buys and demonstrating how OOH/DOOH improves performance in other channels.

• Use ROMI when allocating the marketing budget and proving the value of OOH/DOOH in the media mix.

• Use ROI when connecting marketing to the company’s overall profitability.

By combining these three perspectives, you gain a fairer picture of out-of-home advertising—not as an isolated line item in a report, but as a key component that elevates the effectiveness of the entire media ecosystem.

Programmatic OOH/DOOH – How It Works

Programmatic outdoor advertising means that DOOH is purchased and optimized through the same type of technical ecosystem already utilized for other digital advertising. In practice, it involves three core components working together: the DSP, the SSP, and Ad Exchanges. Together, they manage how digital advertising inventory is made available, sold, and linked to campaign goals. Major industry players such as AdQuick, Vistar Media, Broadsign, VIOOH, and global DSPs like The Trade Desk describe programmatic DOOH in precisely these terms.

Source: AdQuick – “The Complete Guide to Programmatic DOOH Advertising”

DSP (Demand-Side Platform): Where the buyer manages the campaign

A DSP is the tool where advertisers or agencies plan, manage, and purchase programmatic outdoor advertising. Within the DSP, users:

• Set target audiences, budgets, frequency caps, and campaign goals.

• Select relevant DOOH environments, such as Digisize (above or below ground) or MetroVision—Europe’s largest digital format in a subway environment.

• Determine the bids to be placed on specific DOOH impressions (time slots + screens).

In our Swedish prDOOH offering, JCDecaux’s digital street furniture network is accessible via several established DSPs, including:

• Adform: A European full-stack platform with a strong Nordic presence, commonly used for display, video, and DOOH.

• Blis: A platform focused on location and movement data with a built-in DSP for targeted, location-based advertising, including DOOH.

• BidTheatre: A Swedish DSP focused on programmatic display, video, and DOOH, popular among Nordic agencies and advertisers.

• Displayce: A specialized European DOOH-DSP focused on aggregating premium DOOH inventory programmatically.

• DV360 (Display & Video 360): Google’s enterprise DSP, widely used by international agency networks and advertisers for display, video, CTV, and DOOH.

• Hawk: A European omnichannel DSP with a strong focus on location data, audio, and DOOH.

• Perion: A global ad-tech player (including Undertone and formerly Hivestack) with solutions for programmatic DOOH and other digital channels.

• The Trade Desk (TTD): One of the world’s largest independent DSPs, supporting display, video, CTV, audio, and DOOH.

• Vistar Media: A DOOH-specialized player offering both a DSP and an SSP, with a focus on audience targeting and measurement in digital out-of-home environments.

This allows both global and local agencies to purchase the same inventory within the platforms they already use for other programmatic buying. The industry identifies this “openness” as a key strength of programmatic DOOH: the advertiser can choose a DSP based on their specific tech stack, while DOOH inventory remains available in a standardized manner.

Source: AdQuick – Examples of DSPs within programmatic DOOH

SSP (Supply-Side Platform): Where the media owner packages their inventory

An SSP is used by media owners to make their digital OOH inventory purchasable programmatically. Through the SSP:

• Inventory is listed: which screens are available, and in which networks and environments.

• Formats, placement, traffic flows, and other contextual data are described.

• Floor prices and rules for inventory sales are established.

The SSP ensures that the same impression is not sold twice. While a digital screen in a bus shelter, a digital billboard, or another DOOH surface may be exposed to many buyers, each individual impression is sold to only one winning bidder. Globally, SSPs such as VIOOH (JCDecaux’s proprietary programmatic platform) are used to connect premium DOOH inventory to a broad ecosystem of DSPs.

Ad Exchanges: The marketplace in between

Ad exchanges function as the hub between the DSP (the buy side) and the SSP (the sell side). Simply put, the flow looks like this:

1. An impression (or a play block) on a DOOH surface becomes available.

2. The SSP sends a request via the ad exchange to relevant DSPs.

3. The DSPs calculate the value of the impression based on target audience, location, time, campaign budget, etc., and respond with a bid + potential creative variant.

4. The highest qualified bidder wins, and the creative is delivered to the screen.

Everything happens automatically and rapidly. While not in the same millisecond timeframe as mobile advertising, it occurs in real-time or within pre-defined play blocks that suit DOOH logic. Source: Broadsign – Coordinated programmatic DOOH standards

What our Swedish prDOOH offering includes

In Sweden, we offer a programmatic DOOH network featuring:

• Approximately 270 digital surfaces in street furniture environments.

• Around 460 million impressions per month.

• Deal types including Programmatic Guaranteed, non-guaranteed PMPs, and Managed Services.

• CPM levels starting from approximately 140 SEK, depending on selection and pressure.

• Targeting based on network, city, geo-position, time of day, pre-targeting, and various triggers.

The measurement currency is based on VAC (Visibility Adjusted Contacts) via Outdoor Impact 2.0, providing a standardized measure of visible contacts, which is crucial when comparing DOOH with other channels in a programmatic setup. We also collaborate with affiliated data partners such as Adsquare, Locala, and Happydemics to enable advanced audience targeting, measurement, and attribution, such as mobile-based movement patterns or pre/post-campaign brand studies. In addition to the purchasing logic, our network supports real-time DCO (Dynamic Creative Optimization), measurement, and attribution, allowing for dynamic management of both messaging and optimization throughout the campaign period.

Implications for buyers and media owners

For buyers, this means programmatic outdoor advertising can be managed with greater precision than traditional package purchasing. For example:

• Selecting “select” sites in specific neighborhoods.

• Combining different environments to optimize reach, frequency, and VAC.

• Rapidly scaling pressure around a takeover period or campaign.

• Optimizing during the campaign rather than locking everything in advance.

For media owners, SSPs and exchanges mean that digital inventory reaches both local and global buyers while maintaining control over price floors, availability, and priorities. Case studies from entities like MediaCom/GroupM illustrate how programmatic DOOH purchases are used to combine reach with smart management, including through integrations between SSPs like VIOOH and DSPs like Hivestack.

Source: MediaCom (GroupM) – “Why 2020 Was The Year Of Programmatic Outdoor”

OOH and DOOH: Two Sides of the Same Coin

OOH vs DOOH is less about choosing one over the other, and more about how two closely related forms of out‑of‑home advertising can reinforce each other. Classic OOH refers to static formats – posters in shelters (bus shelter advertising), metro advertising, billboards and standalone panels – while DOOH is the digital screen‑based variant. Both are built on the same physical traffic flows and locations, but offer different possibilities in terms of messaging, control and measurement.

OOH: The Stable Backbone

Traditional analogue out‑of‑home comes into its own when the goal is stable, broad presence over a longer period of time. Static advertising in shelters, at bus stops, in the metro and on standalone sites provides constant exposure, around the clock, without being dependent on time scheduling or play‑out data.

By building a network of OOH sites, you can secure high reach within clearly defined environments, with few moving parts and predictable costs. As a result, OOH often functions as the brand backbone of the campaign: it maintains recognition even when other channels move up and down in pressure.

DOOH: Flexibility, Timing and Context

Digital out‑of‑home is particularly powerful when timing, context and flexibility are critical. With DOOH you can control which creatives run, when and where – changing messages throughout the day, differentiating between weekdays and weekends, linking to local events or weather, and using prDOOH to optimise presence based on data.

The same screen in a shelter can therefore play different roles over the course of a day: broad brand‑building messages in the morning, more tactical offers at lunchtime near restaurants or stores, and reminders of evening activities later on. DOOH makes it possible to weave out‑of‑home into the same data‑driven logic as other digital communication.

When OOH and DOOH Work Together – with Clear Sources

Many industry players highlight that the most effective approach is to combine OOH and DOOH rather than replace one with the other. Media.co.uk, for example, describes how the best solution is often to “combine both formats strategically and leverage their respective strengths to achieve a comprehensive outdoor presence” (What is Digital Out‑of‑Home Advertising | DOOH vs Traditional OOH).

International agencies report similar patterns: static OOH builds broad awareness and gives the campaign structure, while DOOH drives engagement and enables more precise targeting and measurement (OOH vs DOOH Advertising: Key Differences and Benefits, via International Advertising Solutions). The common thread is that impact is greatest when the formats are treated as complements, not competitors.

The Choice Depends on the Objective

In practice, the choice between analogue and digital should start from what the campaign is meant to achieve:

• If a launch is intended to create long‑term brand recognition across the city, static formats are often the most cost‑effective way to build broad presence over time.
• If a retailer wants to drive traffic to specific stores within defined time windows – for example weekend promotions, lunchtime offers or evening events – DOOH is more suitable, as messages can be timed and adjusted based on performance.

In many cases, it is the combination that delivers the best results. Analogue out‑of‑home secures breadth and continuity in the environments where the target audience moves, while DOOH is used where time relevance, data‑driven optimisation and rapid adjustments add extra value.

From “OOH vs DOOH” to “OOH + DOOH”

Once the roles are clearly defined, the question becomes less “OOH or DOOH?” and more “how should we size OOH + DOOH in the media mix?”. This aligns closely with how the market describes best practice: static OOH sites as the robust foundation, digital OOH screens as the agile, data‑driven spearhead. Together, they provide both structure and flexibility – and help out‑of‑home deliver its full potential.

Out-of-home advertising, both OOH and DOOH, is primarily purchased to create reach and generate the right level of pressure within a defined target audience. Consequently, three base metrics are used in almost all planning: reach, frequency, and GRP. These are standard in international guidelines and recognized by industry organizations, such as the OAAA and in JCDecaux’s own guides to (D)OOH measurement.

What do reach, frequency, and GRP mean in (D)OOH?

In (D)OOH, these are defined as follows:

• Reach: The proportion of individuals in the target audience exposed to the campaign at least once during the campaign period.

• Frequency: The average number of exposures per reached individual.

• GRP (Gross Rating Points): The product of reach and frequency, often expressed as rating points over time.

Billups describes these as the foundation for planning and comparing OOH campaigns: reach tells you how many people, frequency tells you how often, and GRP provides a comprehensive view of the campaign’s total pressure. The OAAA’s own glossary defines GRP in (D)OOH as a key metric for campaign delivery and for modeling reach and frequency.

How are reach and frequency built in practice?

There are two primary ways to build reach in (D)OOH:

1. Geographic dispersion: Spreading units across multiple areas, neighborhoods, or cities.

   • Result: More unique individuals are reached → reach increases.

2. Concentration in key hubs: Placing units heavily where traffic flows are high and visibility is strong (hubs, city centers, premium sites).

   • Result: Frequency increases relatively faster than reach; i.e., the same individuals encounter the message multiple times.

GRP serves as a tool to balance these effects. Vector Media describes it as a practical compass: should the campaign prioritize reaching as many people as possible (reach) or increasing the number of contacts among those already reached (frequency), given a specific GRP target?

DOOH: Reach and frequency in shared loops

In DOOH, an additional dimension enters the equation: a single screen carries multiple campaigns in a shared spot loop. This means that reach and frequency are governed by both:

• Number of screens and their placement.

• Share of loop: The percentage of the loop your campaign occupies, and during which hours.

At JCDecaux and across the industry, we emphasize that the flexibility of DOOH allows you to:

• Concentrate pressure during specific hours or days when the target audience is most present.

• Dial up the frequency during defined windows (e.g., launch week, evenings, weekends) without needing to change physical sites.

The result is that you can build high frequency among the right people rather than spreading pressure evenly throughout the day.

Best formats for (D)OOH reach, where the “big picture” is crucial

When planning the best formats and networks for reach in (D)OOH, you must consider the big picture:

• A broad network of standardized sites: Provides a stable base reach and ensures that a large portion of the target audience is reached at least once.

• Select sites and premium locations: Used for reinforcement around high-priority areas, such as city centers, retail districts, or transit hubs, where both reach and frequency can be built more rapidly.

• Placement and overlap: By understanding how different traffic flows and locations overlap, you can:

  • Avoid overexposure within certain segments of the target audience.

  • Free up space to add new contacts in other segments.

As Cecilia Ottobre, Sales Director at JCDecaux Sweden, states: “It is the interaction between reach, frequency, and GRP that makes (D)OOH planning effective, not the maximization of a single number.”

Conclusion: Steer toward the right combination, not just high numbers

• Reach tells you how many people in your target audience you reach.

• Frequency tells you how often they are reached.

• GRP connects the two, making it possible to compare campaigns over time and across media.

By combining a broad network of sites with the smart use of “select” and premium formats—and, in DOOH, the right share of loop at the right time—you can steer toward a level where reach, frequency, and GRP support the campaign’s purpose and its role in the media mix, rather than simply chasing the highest possible number of contacts.

In 1964, Jean-Claude Decaux invented the concept of advertising-funded street furniture. This was a truly analog innovation: physical shelters and street-level assets financed by advertising, which laid the foundation for an entirely new business model for out-of-home (OOH) media.

Since then, both advertising and urban environments have undergone a fundamental transformation. With the advent of digitalization, mobile screens, and data-driven marketing, the demand for relevance, flexibility, and measurability has intensified. JCDecaux has evolved in tandem with this shift—transforming from a purely analog player into a company that now offers both classic analog OOH and digital out-of-home (DOOH), with capabilities for programmatic buying and real-time data-driven campaign management.

When JCDecaux became the world’s largest outdoor advertising company in 2011, built on three pillars—street furniture, transport advertising, and billboards—it marked the beginning of a new phase. Today, our mission is to combine the best of both worlds: the scalable reach and urban presence of analog OOH with the precision, dynamism, and measurability provided by digital and programmatically purchased DOOH. In doing so, we continue to develop the core concept established in 1964: making the city more functional, aesthetically pleasing, and relevant for people on the move.

Two Sides of the Same Coin

OOH and DOOH are effectively two sides of the same coin. Both are focused on securing visibility in environments where people move: on streets, in plazas, at transit stations, and within public transport systems. The distinction lies in how the message is displayed and the degree of flexibility available in managing it over time.

Classic OOH (Out-of-Home) consists of static surfaces: bus shelters, street furniture, independent “Eurosize” panels (with public information on one side and advertising on the other), analog subway advertising, and larger-scale billboards such as our “Supersize” format. The message remains displayed 24/7 throughout a campaign period, providing a stable, predictable presence. For brands looking to build broad reach, work with a few clear assets, and keep production simple, this often serves as an effective foundation for the media mix. Standardized networks also simplify planning and procurement for both advertisers and agencies.

DOOH (Digital Out-of-Home) is the digital evolution of the same channel. Messages are displayed on screens rather than posters, allowing for dynamic changes, optimized playback, and time-sensitive communication without the need for physical printing and installation. This becomes particularly compelling when timing and context are paramount: morning messages along commute paths, lunch offers near retail hubs, or campaigns that scale up during weekends or specific events. Examples of these formats include Digisize (standalone street-level screens), MetroVision (Europe’s largest digital network in the subway), and Supersize Digital (a 60-square-meter digital billboard).

Performance and Impact

Research, including studies by JCDecaux and Neuro-Insight, demonstrates that brain response intensifies when a message is contextually relevant, leading to improved ad recall and increased sales. For instance, dynamic, data-driven DOOH campaigns have shown up to 16–17% higher sales and significantly stronger brand impact compared to non-dynamic counterparts (DecisionMarketing / JCDecaux Neuro Study).

Additional studies show that DOOH often drives more immediate action—such as search queries, store visits, or purchases—and is perceived as more innovative and engaging. For example, data from GroupM indicates that consumers frequently report that DOOH campaigns have prompted direct action, with the channel ranking highly in brand experience and creativity.

Strategic Integration: OOH and DOOH

The choice between OOH and DOOH is, therefore, less about “analog vs. digital” and more about the required level of campaign dynamism. If the objective is long-term awareness with a limited number of assets and stable presence, traditional OOH formats are highly effective. However, when a campaign requires high situational relevance—such as price offers, store traffic incentives, or messaging linked to weather, inventory status, or live data—DOOH becomes a more potent tool. Data triggers (such as weather, time of day, or specific events) can be integrated to control when, where, and how various assets are displayed. VIOOH and similar SSP platforms have emerged to make it easier for agencies and advertisers to purchase DOOH programmatically and integrate it into the same planning cycles as other digital channels.

There is also a creative dimension where OOH and DOOH converge. Various creative activations—which we categorize as “Innovate” solutions—can combine physical structures with digital screens and motion content. A “takeover” of a high-impact digital site offers the same effect as a classic dominance campaign, but with the added power of moving imagery, multiple assets, and real-time messaging control. Industry media, such as The Drum, often highlights the combination of physical impact and dynamic, contextual communication as a key reason for the rapid growth of DOOH in global media plans.

Conclusion

In practice, the question is rarely “DOOH or OOH?” but rather “how do we use both to the greatest effect?”

A common strategy for large-scale campaigns is to:

• Utilize static OOH to build broad reach and a stable base presence in key environments.

• Layer DOOH on top to increase relevance over time, manage ad pressure during key moments, and test multiple creative variants.

Research into the interplay between these channels also shows that they do not merely perform well in isolation; they strengthen the effect of other channels. Lumen and JCDecaux have shown that exposure on public screens can “prime” the target audience, causing them to pay greater attention to advertising in digital channels subsequently.

When OOH provides reach and physical presence, and DOOH adds time- and data-driven relevance, the result is a channel that both builds long-term brand equity and drives immediate action. This is where out-of-home advertising, in both its analog and digital forms, reaches its full potential within the media mix.