Do buyer personas really work?

In short: No. There is no peer-reviewed study demonstrating that buyer personas improve marketing results. On the contrary, 60+ years of research from the Ehrenberg-Bass Institute document that any brand's customers are radically heterogeneous and that competing brands share almost overlapping audiences. The evidence-based alternative is Romaniuk's Category Entry Points: purchase situations the brand must be mentally linked to.

• Sharp (2010), How Brands Grow, Oxford University Press — ch. 5: a brand's customers are extremely heterogeneous, no narrow profile represents them. Ch. 8: perceived differentiation between competing brands is minimal.
• Romaniuk & Sharp (2016), How Brands Grow Part 2, Oxford University Press — ch. 2: light buyers make up the majority of the customer base and are the engine of penetration.
• Romaniuk (2018), Building Distinctive Brand Assets, Oxford University Press — ch. 4: growth comes from mental availability and distinctive assets, not from psychographic profiling.
• Binet & Field (IPA, 2013), The Long and the Short of It — broader targeting beats narrow targeting over the medium-to-long term: a positive ESOV requires reach, not profiles.

There is a ritual repeated every day in Italian agencies. The consultant opens the document, types "Buyer Persona" and starts making up profiles of imaginary customers: "Maria, 35, working mum, yoga, vegan cooking, €42,000/year". The client nods, pays, and nobody ever asks: but does it really work?

To answer, we need to step out of folk marketing and look at what the data say. In marketing science — the empirical discipline that grew around the Ehrenberg-Bass Institute for Marketing Science — the verdict is clear-cut: buyer personas have no empirical foundation, and their assumptions have been falsified by peer-reviewed research repeatedly, across thousands of categories and dozens of countries. Below, the evidence.

What a buyer persona is

A buyer persona is a semi-fictitious profile of a company's "ideal customer": it includes demographic data (age, income, location), psychographic data (values, interests, lifestyle), behavioural data (purchase habits, channels), and typically an invented name, a stock photo and a romanticised biography. The concept was popularised by Alan Cooper in the 1990s in software design, then imported into marketing by HubSpot during the inbound boom.

The underlying assumption is simple and seductive: if you know your typical customer inside out, you can craft messages perfectly calibrated for them. The problem is that this assumption does not withstand empirical testing. The main laws of scientific marketing — Double Jeopardy, Duplication of Purchase, Natural Monopoly — converge in indicating that a brand's customers are not a "type" but a heterogeneous population, and that competing brands essentially fight for the same audience.

Why buyer personas don't work (3 pieces of evidence)

1. A brand's customers are heterogeneous, not prototypical

Sharp documents this in How Brands Grow (Oxford University Press, 2010, ch. 5): when you analyse the real customer base of any brand — from soft drinks to financial services — you find a broad distribution across age, income, geography, lifestyle. There is no "typical customer". Creating 3-5 profiles and pretending they represent this variety is, in Sharp's own words, «like describing the ocean with three glasses of water». The statistical model that best describes this distribution is NBD-Dirichlet, not psychographic segmentation.

2. Competing brands share the audience (Duplication of Purchase)

The Duplication of Purchase Law (Goodhardt, Ehrenberg, Chatfield, 1984; Hammond, 1996; Kennedy, 2000; Uncles, 2012) demonstrates a pattern replicated over 50+ years of research: a brand's customers are largely also customers of its competitors, in proportion to the latter's market share. Coca-Cola and Pepsi customers overlap massively; so do Nike and Adidas customers. The corollary: creating "unique" buyer personas for your own brand is an exercise in self-deception. The differences between competing audiences are far smaller than marketers and entrepreneurs believe.

3. Personas exclude light buyers (= growth)

Romaniuk and Sharp, in How Brands Grow Part 2 (Oxford University Press, 2016, ch. 2), show that light buyers — occasional, barely loyal buyers who purchase from many different brands — make up the majority of any brand's customer base, typically well over 50% and often more than 80% of penetration. Growth, according to the Double Jeopardy Law (Ehrenberg, Goodhardt & Barwise, 1990, Journal of Marketing), comes from acquiring more light buyers, not from cultivating heavy buyers. Buyer personas, by focusing on "ideal customers" (= loyal heavy buyers), exclude them by construction. Binet & Field (IPA, 2013) confirm: broad-reach campaigns beat targeted campaigns over the medium-to-long term.

What Byron Sharp and the Ehrenberg-Bass Institute say

Byron Sharp is Professor of Marketing Science at the University of South Australia and director of the Ehrenberg-Bass Institute for Marketing Science, founded by Andrew Ehrenberg and today the leading centre of empirical research on consumer behaviour. The institute's corporate sponsors include Mars, Procter & Gamble, Coca-Cola, Unilever, Meta, Google. His book How Brands Grow (2010) is considered the reference text of evidence-based marketing.

Sharp and his group's position is explicit (How Brands Grow, 2010, ch. 1):

«Most of what marketers think they know about consumer behavior is wrong. Marketing strategies based on segmentation and differentiation typically fail because they contradict empirical laws. Brands grow by reaching more category buyers, not by targeting tighter segments.»

— Byron Sharp, How Brands Grow, OUP 2010

Jenni Romaniuk, Research Professor and Associate Director at the institute, has extended this framework on the perceptual side with the concept of Category Entry Point (CEP): the concrete operational alternative to the buyer persona.

Category Entry Points: the evidence-based alternative

Category Entry Points (CEPs) are the purchase situations, needs and contexts that activate category thinking in the consumer. Instead of asking «who is my customer?» (the wrong question), CEPs ask «in which moments does someone think about my category, and is my brand among those that come to mind?».

Concrete examples (from Building Distinctive Brand Assets, Romaniuk, OUP 2018, and Better Brand Health, Romaniuk, OUP 2023):

• Coca-Cola: CEP = "when I want to refresh myself", "with pizza", "on a break", "for a party". Not "Maria, 35, yoga".
• Accounting firm: CEP = "when I open a VAT number", "at the tax deadline", "for advice on a new hire", "when I change tax regime". Not "Luca, manufacturing SME, 30 employees".
• Shoe e-commerce: CEP = "shoes for a friend's wedding", "for running on Sundays", "for the office", "as a gift". Not "sporty 25-35 B-class".

Romaniuk's operational framework is summarised in the W's model (Building Distinctive Brand Assets, ch. 4): With whom? When? Where? Why? While doing what? How feeling? How's it going?. These are the 7 situational dimensions that define a CEP. The strategic goal is to maximise the number of CEPs the brand is mentally linked to (mental availability).

Buyer Persona vs Category Entry Points: comparison

How to apply CEPs in 2026

Moving from buyer personas to Category Entry Points is a change of operational framework, not just of vocabulary. Here are the concrete steps for an SME.

1. Map 10-15 CEPs of your category

Start from the consumer, not from yourselves. Interview 20-30 category buyers (not just your own customers) with questions such as: «The last time you bought [category], what prompted you? Where were you? With whom? What were you doing beforehand?». Group the answers into distinct CEPs. Goal: a list of 10-15 concrete purchase situations. Romaniuk (Building Distinctive Brand Assets, 2018) recommends aiming for 10+ CEPs covered for a growing brand.

2. Measure the brand's mental availability for each CEP

For each CEP, measure the percentage of consumers who spontaneously mention your brand among the first options. This metric — the Mental Market Share per CEP — predicts long-term performance better than brand awareness (Romaniuk, 2023, Better Brand Health).

3. Prioritise high-potential CEPs

Do not invest in every CEP: prioritise those with high purchase frequency in the category and low mental availability for your brand (= bridgeable gap). They are competitors' soft spots.

4. Build distinctive assets that activate those CEPs

Distinctive Brand Assets (colours, logos, jingles, characters, payoffs) are the bridge between CEPs and memory. A distinctive asset does not say «we're different»: it says «we're recognisable». Creative advertising must explicitly link assets to priority CEPs (e.g. Coca-Cola + pizza, Mulino Bianco + breakfast).

5. Maximise reach on category buyers

Apply the Binet & Field 60/40 rule: 60% of the budget in broad-reach brand building, 40% in activation. Avoid narrow psychographic targeting: Wood (2009, Journal of Advertising Research) and Riebe (2011) show that only 50% of the audience reached through psychographic filters matches the desired profile — ROI is halved from the start.

Frequently Asked Questions

What is a buyer persona?

A buyer persona is a semi-fictitious profile of a company's "ideal customer", with demographic, psychographic and behavioural data, typically equipped with an invented name, stock photo and romanticised biography. The concept was popularised by Alan Cooper in 1990s software design and imported into marketing by HubSpot with inbound marketing. In 2026 it has no peer-reviewed empirical validation.

Why don't buyer personas work?

Because they rest on three assumptions falsified by scientific research: (1) that a brand's customers are homogeneous (refuted by the NBD-Dirichlet model and ch. 5 of Sharp's How Brands Grow); (2) that competing brands have different audiences (refuted by the Duplication of Purchase Law, replicated over 50+ years of studies); (3) that growth comes from "ideal customers" (refuted by Romaniuk and Sharp in How Brands Grow Part 2: growth comes from light buyers, whom personas exclude by construction).

What is a Category Entry Point (CEP)?

A Category Entry Point is a purchase situation — a need, a context, an occasion — that activates category thinking in the consumer. The concept was formalised by Jenni Romaniuk (Ehrenberg-Bass Institute) in Building Distinctive Brand Assets (Oxford University Press, 2018). Example: "when I want to refresh myself" is a CEP for Coca-Cola. A brand grows by maximising the number of CEPs it is mentally linked to (mental availability).

What is the evidence-based alternative to buyer personas?

The evidence-based alternative is Romaniuk's Category Entry Points, combined with broad targeting on category buyers (Sharp), investment in Distinctive Brand Assets (colours, logos, distinctive jingles) and reach maximisation according to Binet & Field's 60/40 framework (IPA, 2013). Instead of asking «who is my customer?», we ask «in which situations must my brand come to mind?».

Who is Byron Sharp?

Byron Sharp is Professor of Marketing Science at the University of South Australia and director of the Ehrenberg-Bass Institute for Marketing Science, the leading centre of empirical research on consumer behaviour, founded by Andrew Ehrenberg. He is the author of How Brands Grow: What Marketers Don't Know (Oxford University Press, 2010) and co-author with Jenni Romaniuk of How Brands Grow Part 2 (OUP, 2016). The institute's corporate sponsors include Mars, Procter & Gamble, Coca-Cola, Unilever, Meta and Google.

Start doing evidence-based marketing

If you are still working on buyer personas and have never mapped your Category Entry Points, you are probably leaving on the table the largest part of your potential market — the light buyers who make up 80% of the category customer base. We at Deep Marketing work exclusively with evidence-based Ehrenberg-Bass frameworks: CEPs, Distinctive Brand Assets, reach-first media planning.

Discover our evidence-based approach to social and content, or let's talk directly: in 30 minutes we'll show you how to turn your buyer personas into an actionable CEP map.

Sources and References

• Ehrenberg-Bass Institute for Marketing Science — About Us
• Sharp, B. (2010), How Brands Grow: What Marketers Don't Know, Oxford University Press
• Romaniuk, J. & Sharp, B. (2016), How Brands Grow Part 2, Oxford University Press
• Romaniuk, J. (2018), Building Distinctive Brand Assets, Oxford University Press
• Binet, L. & Field, P. (2013), The Long and the Short of It, IPA
• Ehrenberg, Goodhardt & Barwise (1990), Double Jeopardy Revisited, Journal of Marketing
• Marketing Science Institute — Research Priorities
• Journal of Advertising Research (ARF)