The best thing about my role at Mobas is that I get to meet with dozens of marketing managers and business owners every year. Each one of them leads in their role from their head, their heart, and often their gut.
Instinct is a powerful business characteristic. It allows leaders to make quick decisions, back themselves, and inspire their teams. But instinct also has its dangers.
Too often, I come across people making decisions based solely on assumptions, and I am consistently shocked at how quickly inaccurate assumptions can become deeply rooted inside organisations. Left unchecked, those assumptions can shape marketing strategies, dictate budgets, and drive campaigns that ultimately fail to connect with customers.
That is why, at Mobas, we use a powerful tool called assumption mapping. It helps us, and the clients we work with, unpick the beliefs behind decisions, evaluate their validity, and prioritise which ones need testing before investment. It is a process that allows us to move away from guesswork and towards evidence-based, insight-driven marketing.
Every business decision rests on assumptions. When we launch a new product, we assume our customers will want it. When we design a campaign, we assume the messaging will resonate. When we choose a channel, we assume our audience will be there and ready to engage.
Some assumptions prove correct. But many do not, and the cost of acting on the wrong assumption can be significant. I have seen businesses invest heavily in campaigns built on flawed beliefs such as:
Without testing, these assumptions are taken as truth. They shape strategy and activity in ways that are hard to unwind later.
Assumption mapping is a collaborative exercise designed to bring those hidden beliefs into the open. It helps teams identify, analyse, and prioritise assumptions so they can test the riskiest ones before making big decisions.
The process is simple but powerful:
List the assumptions
In a workshop setting, teams brainstorm all the assumptions they are making about their customers, their proposition, and their marketing activity. These are usually grouped into three categories:
Desirability – Do customers actually want this? Will it resonate?
Viability – Is this sustainable and commercially sound?
Feasibility – Can we deliver it with the resources and capabilities we have?
Map the assumptions
A two-dimensional grid is drawn:
The Y-axis represents importance: how critical is this assumption to the success of the strategy?
The X-axis represents certainty: how much evidence do we actually have to support it?
Each assumption is then placed on the grid.
Prioritise the risks
Assumptions that fall into the “important but uncertain” quadrant are the ones to focus on. These are the beliefs that could make or break a campaign if they prove false.
Test and validate
With priorities identified, teams can design experiments or research to test assumptions, whether through customer interviews, surveys, A/B testing, or pilot campaigns.
The strength of assumption mapping lies in its ability to turn the invisible into the visible. It creates a shared view of what a team is really basing its strategy on, and it gives leaders clarity about where the biggest risks lie.
For senior marketers and business leaders, it offers several benefits:
At Mobas, we use assumption mapping as part of our strategic consultancy process. It gives our clients a clear sense of where they can move forward with confidence, and where they need to pause, test, and learn before committing.
One NHS client had the long-held view that men would not engage with healthcare advertising. The belief was that men would shy away from, or actively disengage with, any content encouraging them to take a proactive approach to their health. It was a logical assumption, based on anecdotal experience, and it had gone unchallenged for years.
Using assumption mapping, we explored whether this was valid. While there was evidence that some men do ignore healthcare content, we uncovered a deeper truth: the barrier was rooted in fear. Men were not disengaging because they did not care; they were disengaging because they were worried about what they might find out. This insight transformed our approach. By shaping a campaign around the responsibility of family, positioning men’s health as something that mattered not just to themselves but to their loved ones, we unlocked a message that resonated. Engagement rose dramatically because the campaign addressed the real issue, not the assumed one.
In another case, a B2B finance client believed their success was rooted in the breadth of their product range. That assumption had guided much of their strategy, expanding their portfolio and competing on choice. But assumption mapping revealed something different. Brokers consistently pointed to the ease of speaking directly with a knowledgeable team member and receiving a human answer. The breadth of products mattered, but the human connection mattered more.
Armed with this insight, the client shifted focus. They invested in staff retention and engagement, recognising that their people were their true differentiator. It was a subtle yet powerful shift: moving from competing on products to competing on experiences.
Assumption mapping is not about slowing things down. It is about making sure energy is focused in the right place. Instead of spreading effort across dozens of untested ideas, it helps leaders target the few that carry the biggest risks and rewards.
It also creates a culture of curiosity. Teams start to ask: what are we assuming here, and how sure are we? Over time, that mindset reduces bias, encourages evidence-based decision-making, and increases the chances of marketing success.
Instinct will always have a role in business, and rightly so. But instinct without validation can lead us astray. Assumption mapping provides a structured way to challenge beliefs, test ideas, and build strategies that are rooted in evidence.
If you are leading marketing activity, I would encourage you to take a simple first step: list out the assumptions you are making right now about your customers, your channels, and your campaigns. Then ask yourself: how certain am I that these are true?
And if you need help turning those assumptions into a clear plan of action, speak to Mobas. We can help you identify the riskiest beliefs, design the right tests, and make confident, insight-led decisions that set your marketing apart.