The Ehrenberg-Bass Institute: What the Research Actually Says (And What It Doesn't)

Most marketers have heard of Ehrenberg-Bass. Some have read Byron Sharp's How Brands Grow. Fewer can use the research to change a decision. And almost none can translate it into the language a CFO or board member will find credible.

That gap — between knowing the research exists and knowing how to apply it commercially — is exactly where the CMO transition gets expensive. The Ehrenberg-Bass findings are not difficult. They are counterintuitive. And counterintuitive findings are only useful if you understand what they are actually saying, not just the headline version of them.

This is an attempt to give you the real thing.

Who is the Ehrenberg-Bass Institute?

The Ehrenberg-Bass Institute for Marketing Science is a research institute at the University of South Australia in Adelaide. It was founded on the earlier work of Andrew Ehrenberg, a British statistician and marketing researcher whose empirical work across the 1950s through the 1990s documented statistical regularities in buyer behaviour that held across categories and countries.

Byron Sharp, the Institute's current director, extended and systematised Ehrenberg's findings and published them in How Brands Grow in 2010. The book brought the research to a mainstream marketing audience and generated a decade of debate about the implications for brand strategy, loyalty programmes, and media planning.

The Institute's work is not theoretical. It is empirical — built on the analysis of actual buying behaviour data across categories ranging from packaged goods to financial services to automotive. The findings are patterns that hold across a wide range of conditions, not prescriptions derived from theory. That distinction matters when interpreting what the research can and cannot tell you.

The three findings you need to understand

1. Brands grow through penetration, not loyalty

This is the finding that gets the most attention and produces the most confusion. What it actually says:

In most mature categories, large brands and small brands have buyers who purchase with similar levels of loyalty — measured as purchase frequency or share of category requirements. What differentiates large brands from small brands is not that their buyers are more loyal. It is that they have more buyers.

The implication is that the primary lever for brand growth is not increasing how often existing customers buy — it is increasing how many people buy at all. Penetration, not loyalty.

What this does not say: that loyalty is worthless. Loyalty programmes, retention efforts, and customer experience investment all have commercial value — particularly in categories where lifetime value is high and switching costs are real. What the research says is that loyalty alone cannot drive category-level brand growth. A brand cannot meaningfully grow its market share primarily by making its current buyers slightly more frequent. It has to recruit buyers it does not currently have.

2. Double Jeopardy

Double Jeopardy is perhaps the most empirically solid finding in the Ehrenberg-Bass body of work. It is also the most consequential for how CMOs should think about budget allocation.

The pattern: small brands are penalised twice. They have fewer buyers than large brands (the first jeopardy). And among the buyers they do have, those buyers purchase the small brand less often and are more likely to switch than buyers of larger brands (the second jeopardy).

This is a structural feature of markets, not a failure of small brand management. It holds across categories, countries, and time periods. The small brand's lower loyalty is not caused by a loyalty programme deficiency or a brand experience gap. It is caused by smaller brands simply being less present in buyers' minds — lower mental availability — which means buyers think of them less often when a purchase occasion arises.

For the CMO of a challenger brand, the strategic implication is uncomfortable: the larger brand does not need to work as hard to hold its position as the challenger does to gain on it. The market structure itself favours the incumbent. Growing market share requires excess share of voice — spending proportionally more on marketing than your current share of market — because that is the mechanism by which mental availability catches up.

3. Mental availability and physical availability

Sharp's translation of Ehrenberg's findings introduces two concepts that have become the most useful outputs of the research for practical brand strategy: mental availability and physical availability.

Mental availability is the probability that a buyer will notice, think of, or recall a brand in a buying situation. It is built through reach — the breadth of exposure to the brand across the population — and through the association of the brand with the range of contexts in which the category purchase happens. These contexts are called category entry points.

Physical availability is the ease with which a buyer can find and purchase the brand when they want it — through distribution depth, shelf placement, prominence, and format variety.

The research argues that both are required, and that most brand strategy over-weights mental availability at the expense of physical, or over-weights physical at the expense of mental. The two compound: a brand that is widely distributed but not memorable is easy to find and rarely thought of. A brand that is highly salient but narrowly distributed is thought of and not found.

For the CMO, these two concepts reframe the growth question. Not "are our ads effective?" but "do enough people in this category think of our brand in enough of the occasions when a purchase could happen, and can they find and buy us when they do?"

What the research challenges

Understanding Ehrenberg-Bass requires knowing which comfortable assumptions it directly contradicts — because those contradictions are where the commercial value sits.

The loyalty-first assumption

Many brand strategies are built on the assumption that the most valuable thing marketing can do is deepen the relationship with existing customers. Increase retention. Build community. Drive purchase frequency. This assumption is intuitive, easy to measure, and — in most categories — insufficient as a primary growth strategy.

The research does not say ignore retention. It says that in most categories, the buyers who drive volume growth are not the brand's heavy loyalists — they are the category's light buyers, people who buy the category infrequently and the brand occasionally. There are simply more of them. A campaign designed to reach and resonate with occasional buyers, rather than to deepen the relationship with committed loyalists, will usually produce larger commercial returns at scale.

The niche targeting assumption

Digital advertising has made precision targeting technically easy and commercially tempting. A brand can now reach exactly the buyers who look most like its existing customers, at scale, with relatively low wasted reach.

Ehrenberg-Bass challenges the commercial logic of this approach at the brand level. If growth comes from penetration — from recruiting new buyers, particularly light buyers — then a strategy that focuses exclusively on people who already look like your customers is selecting precisely the group that is least likely to drive incremental growth. The most commercially valuable buyers, from a market-share-growth perspective, are the ones who have not bought yet.

This does not make precision targeting wrong — for activation, for direct response, for retention-focused communication, it remains highly effective. What it challenges is using precision targeting as the primary mechanism for brand growth. Reach — the breadth of exposure across the buying population, including people who do not currently buy your brand — is the mechanism that builds mental availability at scale.

The distinctive assets question

One practical output of the Ehrenberg-Bass mental availability framework is the concept of distinctive brand assets — the specific visual and sonic elements that allow a buyer to immediately identify a brand: a colour, a logo, a character, a sonic signature, a pack shape.

The research distinguishes between brand elements that are distinctive — strongly owned by one brand in the category — and elements that are merely different. A distinctive asset triggers brand recognition. A merely different element might be noticed without creating attribution.

For the CMO, this is operationally significant. It argues for protecting and consistently using a small set of distinctive assets across all communication, rather than refreshing the creative approach with each campaign or each channel. The distinctive asset is an investment that builds recognition over time. Changing it resets the investment.

What the research does not say

The Ehrenberg-Bass findings have been misread in both directions. Some marketers use them to dismiss loyalty as irrelevant. Some sceptics dismiss them as too simple for real categories. Both misreadings are worth correcting.

The research describes patterns in aggregate buying behaviour. It does not claim those patterns apply equally in every category. In categories where switching costs are high — enterprise software, financial services, professional services — loyalty dynamics look different. In categories with strong subscription mechanics, purchase frequency behaves differently than in categories with impulse-driven repertoire buying.

The CMO's job is to understand which market law applies in their category — not to assume the FMCG packaged goods data applies everywhere, and not to assume it does not apply because their category seems different.

The honest version: the Ehrenberg-Bass research is the most replicated body of empirical evidence in marketing science. It describes what happens in most markets, most of the time, with a high degree of consistency. The CMO who understands it can predict where their brand is in the market structure, what the likely growth mechanisms are, and why certain common strategies are likely to underperform. That is the practical value.

How to use this in a board conversation

The Ehrenberg-Bass research is most useful to the CMO not as a strategy document — it is research, not prescription — but as an evidence base that makes the commercial argument for brand investment credible to a financially literate audience.

When the CFO asks why you are investing in broad-reach brand building rather than targeted performance, the Ehrenberg-Bass finding on penetration growth is the answer: "In our category, growth comes primarily from increasing the number of buyers, not from increasing purchase frequency among existing buyers. Broad reach is how we access those buyers. Here is the empirical basis for that claim."

When the board asks why brand investment takes so long to show results, the Double Jeopardy and mental availability framework explains it: building the mental availability that eventually converts to purchase takes repeated exposure over time. The timeline is not a sign of inefficiency — it is a property of how memory and category salience work.

When the finance team challenges the brand budget by pointing to poor attribution, the distinction between mental and physical availability explains what attribution cannot see: the brand exposure that reduced the cost of the performance conversion. Blended CAC, tracked over time, is the instrument that makes the invisible visible.

None of these arguments require the board to take the research on faith. They require the CMO to have read and understood it well enough to present it as evidence rather than opinion. That is the translation work the CMO role requires.