In short: Light buyers — occasional shoppers who buy a brand once or a few times a year — make up 70-80% of any brand's customer base. Sixty years of Ehrenberg-Bass research show that growth happens through penetration (new light buyers), not frequency. The Double Jeopardy Law penalises small brands twice; the remedy is broad reach, mental availability and distinctive brand assets.
- Penetration growth accounts for more than 70% of revenue growth according to analysis of 4,000 brands — Bain & Company (2024)
- Nielsen confirms that in FMCG light & non-buyers represent the dominant growth reserve for 9 out of 10 categories — Nielsen Consumer Panel
- The SOV > SOM rule + broad reach remains the most robust evidence for reaching light buyers — Binet & Field, IPA
In 2026 Italian marketing keeps investing disproportionate resources on customers already acquired — loyalty programmes, hyper-segmented CRM, obsessive retargeting — while the real growth reserve lies elsewhere. Six decades of research from the Ehrenberg-Bass Institute, confirmed by Nielsen and Bain, show that brand growth depends almost entirely on acquiring new occasional buyers (light buyers), not on increasing the frequency of heavy buyers. This guide explains why, with numbers, academic sources and practical implications.
Frequently Asked Questions
Who are light buyers?
A light buyer is a consumer who buys a brand at low frequency — typically once or very few times a year. In many categories this means people who buy the product only once every twelve months, or less. According to the Ehrenberg-Bass Institute, light buyers make up 70-80% of the customer base of almost every brand and have few memory structures linked to the brand. They are not “loyal” in the traditional sense, but neither are heavy buyers, really: exclusive loyalty is a statistical exception, not the norm.
Why does growth come from penetration and not frequency?
Because that is what the data consistently show. Bain & Company's 2024 analysis of over 4,000 brands found that penetration growth accounts for most revenue growth, while purchase frequency stays relatively stable. The Ehrenberg-Bass Institute has replicated the same pattern since 1960 across thousands of categories. When a brand grows, it does so because more people buy it at least once, not because existing customers buy twice as much.
What is the Double Jeopardy Law in marketing?
The Double Jeopardy Law, formalised by Ehrenberg, Goodhardt and Barwise (1990), states that brands with smaller market share suffer a double penalty: they have fewer buyers (lower penetration) and those few buyers are less loyal (lower frequency). It is a statistical regularity documented in hundreds of peer-reviewed studies, not an opinion. It implies that loyalty is mostly a consequence of penetration, not a cause: first you grow penetration, then you get a little more loyalty as a side effect.
Aren't heavy buyers the most important customers?
They are important for current revenue, not for future growth. The Law of Buyer Moderation (Ehrenberg) shows that this year's heavy buyers tend to regress toward more normal purchase behaviour the following year, by pure statistics. Investing heavily in their retention has diminishing returns. Nielsen research on FMCG confirms that incremental growth potential lies with light and non-buyers, not with already saturated heavy buyers.
Do these laws apply to B2B?
Yes. The LinkedIn B2B Institute, in collaboration with Ehrenberg-Bass, has confirmed that Double Jeopardy, the importance of penetration and the role of light buyers also apply to B2B markets. Business buyers exhibit repertoire patterns, low loyalty and mental-availability-based choice very similar to consumers — in the end, B2B decisions are also made by humans with the same cognitive limits.
How do you concretely reach light buyers?
With three levers: broad reach (communication that reaches the whole category, not only existing customers), distinctive brand assets (colours, logo, sounds, shapes repeated with obsessive consistency to build mental availability) and physical availability (distribution, category SEO, marketplace presence). The Share-of-Voice > Share-of-Market rule documented by Binet & Field for the IPA indicates that brands investing proportionally more than competitors in communication grow over the medium term.
The heavy-buyer bias: why everyone makes the same mistake
When you look at sales data, heavy buyers stand out: they buy often, spend a lot, seem like the “best” customers. The Pareto principle — 20% of customers generate 80% of revenue — becomes an organisational mantra. From there the spiral begins: loyalty programmes, CRM segmentation, exclusive offers for top clients, high-frequency retargeting.
The problem is that the apparent concentration is largely a statistical artefact. As documented by Ehrenberg, Uncles and Goodhardt (2004) in the Journal of Business Research, heavy buyers are over-represented in data simply because they are more exposed to brand messages: buying more often, they interact more often with communications. They are not more “important” for growth — they are just more visible.
It is as if a hospital concluded that the sickest patients were the most important because they occupy more beds. Technically true. But to improve public health you need to address the general population, not just intensive care. The same logic applies to marketing: to grow the brand you need to talk to those who don't buy yet or buy rarely, not to those who already buy every week.
This bias produces three recurring mistakes: overestimating the value of loyalty, underestimating the number of light buyers, allocating budget toward those who already buy instead of investing to reach those who don't even remember the brand. The topic mirrors the one addressed in our guide on buyer persona pseudoscience and evidence-based targeting: both drifts arise from a naive reading of first-party data.
The Ehrenberg-Bass evidence: growth comes from penetration
The Ehrenberg-Bass Institute for Marketing Science, founded at the University of South Australia, is the leading empirical research centre on buying behaviour. Their central thesis, summarised in the two volumes How Brands Grow by Byron Sharp (2010) and How Brands Grow Part 2 by Romaniuk & Sharp (updated 2022), is that brand growth happens almost exclusively through increased market penetration, that is by acquiring new buyers — including and especially light buyers.
This is not an opinion. Romaniuk and Wight, in Marketing Letters (2017), tested the law on 60 brands across 10 categories and 7 countries confirming the pattern. Trinh, Dawes and Sharp (2023) replicated the analysis on buyer groups showing that incremental growth comes from increasing light and non-buyers, not from intensifying heavy buyers. Bain & Company, in a 2024 report covering over 4,000 global brands, concluded that penetration explains the majority share of revenue growth, while frequency varies marginally.
Put bluntly: Coca-Cola did not become Coca-Cola because its fans drink ten cans a day. It became Coca-Cola because billions of people drink one once in a while. The practical implications are radical: more people buying occasionally beats fewer people buying often. The brands that grow are the ones that continuously widen the base, not those that squeeze who's already inside.
Double Jeopardy and Natural Monopoly
Two empirical laws govern the life of brands, and they are often ignored because they are not very spectacular.
Double Jeopardy
Discovered by McPhee (1963) and formalised by Ehrenberg, Goodhardt and Barwise (1990), the Double Jeopardy Law states that brands with smaller market share have both fewer buyers and slightly lower purchase frequency per buyer. It is not cosmic unfairness: it is a statistical regularity documented in over fifty years of replications. Corsi, Rungie and Casini (Australasian Marketing Journal, 2017) confirmed the law's robustness after half a century of testing.
For a small Italian SME the lesson is clear: if you are a small brand and think you can grow by “retaining” the few current customers, you are fighting a law of nature. Loyalty is largely a function of penetration, not a cause. First you grow, then — as a mechanical consequence of size — loyalty increases.
Natural Monopoly
Closely related, the Natural Monopoly Law establishes that larger brands attract a greater proportion of the category's light buyers. Why? Simple: light buyers buy rarely and when they do they pick the brand most easily available in their memory — statistically, the biggest, the most present, the most visible.
Big brands therefore have a natural monopoly on light buyers, who are loyal to no one but buy whoever comes to mind. And who comes to mind is whoever invests more in mental availability and physical availability. For small brands, ignoring light buyers means giving up the largest growth reserve in existence.
Duplication of Purchase and regression to the mean
The Duplication of Purchase Law, replicated by Hammond, Ehrenberg and Goodhardt (1996) and later by Uncles, Ehrenberg and Hammond (Marketing Science), states that every brand shares its customers with competitors in proportion to the market share of each competitor. In practice: if Brand A has 30% market share and Brand B 10%, about 30% of B's customers also buy A, while only 10% of A's customers also buy B.
The implications demolish several myths of traditional marketing: customers of small brands are almost all also customers of big brands; there are no “exclusive segments” loyal to a single brand; brands don't compete for specific segments, they all compete against all for the attention of the same consumers. Differentiation doesn't create protected niches — at most it creates a slight competitive advantage that only works when paired with wide distribution and mass reach.
On top of this comes the Law of Buyer Moderation: this year's top 20% of buyers will generate about 60% of current sales, but next year the same individuals will generate about 45%, because part of them will return to more normal purchase levels. It is regression to the mean applied to purchase behaviour: those exceptionally heavy in one period tend to normalise in the next. Investing heavily in heavy-buyer retention therefore has diminishing returns, while the ocean of light buyers remains intact.
Heavy buyers vs light buyers: the decisive table
How to reach light buyers in 2026: six practical levers
Demolishing illusions is the first step. The second is building. Here is how to concretely reach light buyers, with operational levers aligned with the empirical evidence.
1. Build mental availability
Light buyers don't think about your brand. They don't look for you, don't follow you on social, don't read your newsletters. You have to be the one entering their head, building memory associations between the brand and the category's typical purchase situations (category entry points, a key concept by Romaniuk). Tools: broad-based communication, not hyper-targeted, advertising that reaches the whole category and not just the “ideal target”.
2. Maximise physical availability
A light buyer will not make an effort to find you. You have to be where they are, at the moment they decide to buy: pervasive distribution, presence on physical and digital shelves, frictionless checkout. In 2026 physical availability also includes category SEO (not just brand SEO), marketplace presence, Google Shopping, local SEO, all the touchpoints where the consumer searches for the category.
3. Broad reach, not hyper-targeting
Counter-intuitive in the performance-marketing era, but the data are clear: extreme targeting systematically excludes light buyers. If you retarget only those who already visited the site, you speak only to those who know you. If you use lookalikes of heavy buyers, you replicate the bias. The Share-of-Voice > Share-of-Market rule documented by Binet & Field (IPA) shows that brands with communication investment higher than their market share grow over the following 2-3 years.
4. Distinctive, not differentiating creativity
The difference is subtle but crucial. “Differentiating” means communicating why you are different from others. “Distinctive” means being immediately recognisable even to those who give a tenth of a second of attention — that is, light buyers. Invest in distinctive brand assets (colours, logo, sounds, characters, slogans) repeated with obsessive consistency. Romaniuk, in Building Distinctive Brand Assets (2018), documents how distinctive assets are the only effective cognitive shortcut for occasional buyers.
5. Tangible innovation for small brands
Is there a margin to challenge Double Jeopardy? Yes, but it is narrow. Sethuraman (Journal of Marketing Research, 2006) and Gielens (Journal of Marketing Research, 2012) show that consumers choose smaller brands when they perceive authentic quality and tangible innovation. Caveat: we mean real innovation — new products that solve concrete problems, objectively superior quality — not cosmetic rebranding. It is the only shortcut for small brands: being genuinely better at something perceptible.
6. Continuous presence, not intermittent campaigns
Light buyers buy rarely. That means you don't know when they will buy. If you run campaigns only at Christmas and in June, you lose all the light buyers buying in the other ten months. The right strategy is constant communication pressure, even at low intensity, rather than peaks followed by silence. Binet & Field recommend a 60% brand / 40% activation mix as a robust balance for most categories.
Channel-by-channel strategies: what really works
Do you need to build a brand that reaches light buyers?
Deep Marketing supports Italian brands in building distinctive identities, mental availability and evidence-based reach strategies. Request a brand audit or explore our branding and visual identity consulting to design distinctive assets that work on occasional buyers too.
Sources and References
- Sharp, B. — How Brands Grow: What Marketers Don't Know, Oxford University Press (2010)
- Romaniuk, J. & Sharp, B. — How Brands Grow Part 2 Revised Edition, Oxford University Press (2022)
- Trinh, Dawes & Sharp — Where is the Brand Growth Potential? An Examination of Buyer Groups, Marketing Letters (2023)
- Bain & Company — The Biggest Contributor to Brand Growth (2024)
- Nielsen — Understanding Light Buyers and Their Impact on CPG
- Ehrenberg-Bass Institute — How Do You Measure ‘How Brands Grow’?
- Corsi, Rungie & Casini — Double Jeopardy 50 Years On, Australasian Marketing Journal (2017)
- IPA — Les Binet & Peter Field, The Long and the Short of It (60/40 rule)
- LinkedIn B2B Institute — Research on B2B Buying Behavior
