The model works. Does your story? Tim Harford’s rules for effective MMM storytelling 

Welcome to the wheelhouse, where we discuss critical topics for marketers who want to maximise advertising effectiveness. 

In this edition of The Wheelhouse, Director Etrit Mahmutaj tackles the industry’s blind spot: MMM techniques continue to evolve, but too often the storytelling that makes insights matter is neglected. Inspired by economist Tim Harford’s framework on data responsibility, Etrit reveals what separates trusted advisors from data reporters. 

The importance of storytelling in MMM 

There are many articles these days written by practitioners that put a lot of emphasis, and rightly so, on data quality and strong modelling practices, and how that helps foster a strong marketing effectiveness culture.  

But there’s a critical skill that gets neglected in the rush to meet deadlines: storytelling. It emerges in the final phase of projects when decks are built and results presented, yet it often receives the least attention. This is where trust is built or broken, where insights become action or gather dust. 

At a recent talk, economist Tim Harford (whose book The Undercover Economist helped shape my path into econometrics) outlined three rules for using data responsibly. His framework, “The Three Cs” (Be Calm, Get Context, Be Curious), struck me as the missing piece in how we present marketing effectiveness insights. These aren’t soft skills. They’re the difference between data that sits in a deck and insights that drive decisions. 

Be Calm 

Data triggers emotions. ROI numbers particularly so. Months of media planning and significant investment condensed into a single figure naturally provokes reaction. 

A high ROI? “Excellent, let’s double down.” A low ROI? “This can’t be right.” 

Both responses risk poor decisions. Emotions override analysis. Confirmation bias takes control. Harford argues we must present data (and receive it) with calm, because failing to do so allows emotions to drive interpretation rather than evidence. Though our audience are marketing and media experts, human nature means we all evaluate evidence in ways biased toward our preconceptions. 

So how do we present results in ways that promote calm, rational response? 

1. Complement ROI with spend levels or net profit. Size and scalability matter. A 15:1 ROI on £5,000 spend tells a different story than 3:1 on £500,000. Without this context, strong ROI figures can lead to unrealistic scaling expectations. 

2. Show the “why” behind the number. Don’t just present ROI. Explain whether effectiveness, cost, or value drove the result. Was inventory costly? Have channels hit diminishing returns? Is the creative wearing out? Breaking down the components helps your internal stakeholders understand what’s actually driving performance. 

3. Frame results as learning, not grades. Move from “what happened” to “what we’ll do next.” ROI should inform future decisions, not judge past ones. This shift in framing reduces defensiveness and opens space for productive planning conversations. 

4. Set expectations before delivery. If results contain challenging news, brief key stakeholders in advance. The meeting should focus on solutions, not shock. This simple practice can transform a difficult presentation into a collaborative problem-solving session. 

Get Context 

Context transforms data into insight. An ROI figure alone tells you only whether your channel is profitable or not. Harford stressed that lack of context creates assumption gaps where people have data but not the full picture. Practitioners must add layers that enable clear interpretation and actionable recommendations. 

1. Compare against previous periods. Most companies think year-on-year. Present ROIs accordingly and surface narratives: “Q1 ROI down 10% YoY due to 25% CPM increase.” This speaks their language and immediately connects current performance to business reality. 

2. Feature industry benchmarks. Show whether your channels perform on par with industry standards or outperform them. Resources like the Profitability 2 study (to which Ebiquity contributed alongside other agencies and consultancies) provide ready comparisons. This external perspective can validate strong performance or highlight improvement opportunities. 

3. Do your homework. What was your business’s objective with the channel? Were there delivery challenges? Supply issues? Creative delays? Including this context in your commentary reminds your internal stakeholders of the goals they were chasing and difficulties they encountered during campaign planning. It shows you understand your business, not just your data. 

Be Curious 

Statistics offers us a way to understand the world, but only when we engage with it curiously. That curiosity is increasingly rare in an information age where scepticism often wins over engagement. Harford was passionate about this final point: more people across all walks of life are refusing their curiosity. 

1. While marketers have a responsibility to be curious, the onus is on MMM practitioners to enable it by delivering insights that add unexpected value. This is where we move from competent to exceptional. 

2. Zoom in on effectiveness, cost, and value. Did ad spend go too hard in certain weeks? Are you buying longer spots when shorter ones deliver better value? Such questions can lead to powerful insights about optimal delivery weight and spot length mix, which in turn spark curiosity for future campaigns. These are the conversations that extend beyond the presentation. 

3. Look beyond media. What are the general market trends? How is your product priced relative to competitors? Is category demand growing or declining? Such investigations can shed further light on media performance in ways the model alone cannot capture. Sometimes “underperforming” media is simply fighting against stronger headwinds. 

4. Connect insights across workstreams. Insights from media governance, brand health reports, perceptual maps, or creative testing (such as System1) can enhance MMM deliveries when there’s a common story to share. When multiple data sources point to the same narrative, confidence in recommendations increases dramatically. 

From data reporter to trusted advisor 

In a world increasingly sceptical of data, storytelling isn’t a soft skill. It’s a guardrail against misuse and inefficient outcomes. 

By embracing Harford’s Three Cs, MMM practitioners can elevate our role from data reporter to trusted advisor, ensuring insights not only add up but drive effective marketing decisions. The technical excellence remains essential, but it’s the story we tell around it that determines whether our work creates real impact.