In today’s fragmented media landscape, proving return on investment (ROI) is more important and more complex than ever. Whether allocating a budget to Connected TV (CTV) or Out-of-Home (OOH/DOOH), media planners and buyers must understand how to link media activity to business outcomes. At The Media Planning & Buying Agency, we specialise in creating measurement frameworks that deliver clarity and accountability across all channels.
General ROI Principles
ROI in media campaigns is understood as:
ROI = (Revenue – Media Cost) / Media Cost
Or, how many pounds/dollars you earn for every pound/dollar invested. Sometimes the metric is expressed as Return On Ad Spend (ROAS).
ROAS = Revenue / Media Cost
If a campaign delivers £500,000 revenue and costs £100,000, ROAS = 5 (£5 per £1 spent), and ROI = 4 (400% profit).
However, the challenge lies in attributing which revenue is truly incremental, meaning the lift directly from the campaign that would not have happened otherwise. That involves differentiation from baseline sales, accounting for seasonality, outside factors, and spillover from other media.
Key Principles for ROI Measurement
- Define Incrementality & Baseline: Establish what would likely happen without the campaign (control group, historical trends, seasonality).
- Use Multiple Attribution Approaches: First touch, last touch, multi-touch, media mix modelling, marketing mix, and uplift analysis.
- Align to Business Goals: Not every campaign needs to drive direct sales; some are for awareness, brand lift, or long-term effects.
- Control for Other Variables: External promotions, competitor activity, and macro trends all need to be considered or controlled.
- Track KPIs Along the Funnel: Impressions, reach, frequency, engagement, view through, click, conversions, footfall, among others.
Measuring CTV Campaign ROI
Relevant Metrics & Attribution Methods
- Impressions & Reach: Number of households or users served.
- Completion Rate: Since many CTV ads are unskippable, the completion rate is a crucial metric to ensure your creative is actually seen.
- Cost per Completed View (CPCV): Media cost divided by the number of fully watched impressions.
- View-Through Conversions: Linking a conversion or site visit to someone who viewed the ad, even if they didn’t click directly.
- Attribution/Lift Studies/Holdout Experiments: Running control vs exposed groups to observe differential conversion rates.
Reporting to Stakeholders
- Express results as £X per £1 spent rather than platform metrics.
- Transparently show assumptions, control groups, and confidence intervals.
- Highlight not just short-term sales uplift, but longer-term brand effects as relevant.
Measuring OOH/DOOH Campaign ROI
Common Attribute & Measurement Methods for OOH
- Foot Traffic/Store Visitation: Utilise mobile location data or geofencing to track the number of people exposed to the OOH creative who entered the nearby store, and compare this to control zones.
- Sales Uplift: Compare sales data before, during, and after the campaign period in areas served by OOH versus areas not served.
- Brand Lift: Survey exposed vs non-exposed consumers to measure changes in awareness, ad recall, and purchase intent.
- Cross Media Attribution & Incremental Reach: OOH can deliver incremental reach that is not captured by digital or TV channels.
Best Practices for OOH ROI Measurement
- Use multiple measurement levers (foot traffic, sales, brand lift).
- Monitor decay and wear-out; how long after exposure do the effects last?
- Consider contextual and location modifiers (screen visibility, dwell time, viewing angle, environment).
- Use dynamic or programmatic OOH to deliver relevancy and tie into triggers (weather, time) to strengthen attribution.
- Leverage real-time DOOH data and integrate with digital campaigns for cross-channel synergy.
Challenges, Advanced Methods, & Recommendations
Challenges in ROI Measurement
- Attribution Ambiguity: Overlap between channels, exposure outside tracked windows.
- Time Lag & Decay: Campaigns may influence sales days or weeks after they are implemented.
- Data Limitations: Limited access to third-party data, privacy constraints, and measurement gaps.
- Ignoring Long-Term Effects: Brand building returns aren’t instantly monetisable.
Advanced Approaches & Emerging Methods
- Predictive Incrementality By Experimentation (PIE): A hybrid approach using randomised trials where possible, then extrapolating causal effects to other campaigns without trials.
- Media Mix Modelling & Incrementality Hybrid: Combining MMM with real-time experiments to get both macro and micro insight.
- Unified Measurement Platforms / Identity Graphs: Bridging exposures across screens, devices, and locations to link audience touchpoints better.
Recommendations for Agencies & Clients
- Start with clear objectives and KPI alignment before launching campaigns.
- Deploy control groups wherever possible to isolate performance.
- Integrate data from sales, CRM, footfall, and loyalty programs to enrich attribution.
- Use regular reporting to recalibrate campaigns mid-run.
- Educate stakeholders on the difference between short-term conversion and long-term brand value.
- Build cross-channel synergies so CTV, OOH, and digital campaigns reinforce one another.
Measuring ROI in modern media campaigns, whether through CTV, OOH/DOOH, or across a multi-channel mix, is no longer optional; it’s essential. The key lies in careful design: defining baseline, deploying control groups, layering attribution methods, and interpreting results in business terms. While challenges persist (attribution, lag, limited data), advanced methods and hybrid modelling bridge many gaps.
If you’re planning a media campaign that spans screens, streets, and homes, and you want confidence in your returns, The Media Planning & Buying Agency can help you incorporate measurement into every stage. Contact us and let’s build campaigns that prove their worth.
