How Brands Grow: Byron Sharp on mental and physical availability and light buyers

Who Byron Sharp is, and the core idea

Byron Sharp is a professor at the Ehrenberg-Bass Institute for Marketing Science at the University of South Australia. His book How Brands Grow: What Marketers Don't Know (Oxford University Press, 2010) set out to give evidence-based answers to everyday marketing questions, such as how advertising works, what price promotions do and whether loyalty programmes change loyalty. It presents decades of the Institute's research in a form aimed at working marketers who want to grow their brands.

Several of those patterns challenge common marketing habits. Sharp summarises them in his response to critics on the Institute's website:

• Penetration drives growth. Brands with more sales in a period are bought by more people in that period. Growth comes mainly from more buyers, plus existing buyers buying a little more often.
• Double jeopardy. Bigger brands have more buyers and slightly higher loyalty and attitude scores. Small brands suffer twice: fewer buyers, who are also slightly less loyal.
• Most buyers are light buyers. The vast majority of a brand's buyers buy it rarely, so growth depends heavily on nudging these people.
• Loyalty is real but divided. Buyers are loyal to a repertoire of brands rather than to one.
• Behaviour shapes attitudes. Attitudes follow buying more than they cause it.

The practical conclusion, in Sharp's words to Mi3 in 2022:

"Growth and maintenance largely depends on mental and physical availability." — Byron Sharp, Mi3 interview

Mental availability: being thought of

Mental availability is how easily a brand comes to mind in buying situations. The Institute describes it as being easily thought of by as many category buyers as possible, as often as possible. Without it, a brand simply does not get bought.

Its building blocks are category entry points. The Ehrenberg-Bass Institute defines these as the thoughts category buyers have as they move towards a purchase: the needs, occasions, places and moods that start the search. A seafood retailer's entry points might include a weekend dinner party, a quick weeknight meal or Chinese New Year. The more of these situations a brand is linked to in buyers' memories, the more often it gets considered.

Physical availability: being easy to buy

Physical availability is about the brand being easy to find and buy, which is more than distribution. A 2025 Ehrenberg-Bass report on B2B by Magda Nenycz-Thiel and Jenni Romaniuk, Easy to Find, breaks it into three dimensions:

• Presence: being where buying happens, or could happen, across sales channels.
• Prominence: being easy to spot in sales environments, through paid placement or through the brand's own distinctive assets.
• Portfolio: offering products that meet current and future buyer needs.

The report also notes that physical availability amplifies mental availability, so the two should be built together. And it observes that many B2B brands have little to be recognised by beyond a logo.

Distinctive brand assets: the link between the two

Distinctive brand assets are the non-name cues, such as colours, shapes, logos, characters, sounds and taglines, that trigger the brand in buyers' minds. They help people notice advertising and recognise the brand at the moment of purchase. Jenni Romaniuk, also of the Ehrenberg-Bass Institute, set out how to build and protect them in Building Distinctive Brand Assets (Oxford University Press, 2018).

"Distinctiveness is looking like you and not like others" — Jenni Romaniuk, Contagious

In a Contagious interview, Romaniuk explains two measures. Fame is the share of category buyers who link an asset to your brand when they see it without the name. Uniqueness is how far the asset belongs to you alone rather than being shared with competitors. She warns that marketers tend to overestimate their own asset strength, and that changing assets too often weakens them.

Why it matters for SMEs

Smaller brands feel double jeopardy most sharply: fewer buyers and slightly lower loyalty. Many respond by focusing on their most loyal customers through retargeting, loyalty schemes and discount emails. Sharp's evidence suggests that this caps growth, because the large pool of light and non-buyers is where most of the upside lies. In 2022 he advised marketers to reach everybody and to advertise continuously rather than in occasional bursts.

A practical playbook

1. List your category entry points. Ask recent buyers what was happening when they started looking. Group the answers into needs, occasions and triggers.
2. Pick the entry points you can credibly own and build advertising and content around those situations, not just around product features.
3. Audit your distinctive assets. Show category buyers your colour, logo, pack or character without the brand name and ask who it belongs to. Low fame or low uniqueness means more work to do.
4. Use the strongest assets everywhere and keep them stable. Website, ads, packaging, marketplace listings and social profiles should all look recognisably like you.
5. Plan for reach, not frequency among fans. Check what share of your media reaches people who have never bought from you.
6. Map presence. List every channel where your category is bought, from marketplaces to distributors, and compare it with where you are actually present.
7. Improve prominence and portfolio. Make sure listings stand out, and that your core range covers the main needs buyers bring to the category.

Limits and criticism

The Ehrenberg-Bass approach has vocal critics. Sharp's own rebuttal page lists the most common objections: that it ignores emotion, denies loyalty or relies on cross-sectional data. He answers each in turn. There is also a running disagreement with Binet and Field over budget rules such as 60:40. In our view, Sharp's patterns describe markets on average and are less prescriptive about creative quality or about very small niche markets where a few customers make up most sales. Use them as a strong default, then test against your own customer data.

FAQ

Sources

• How Brands Grow: What Marketers Don't Know — Byron Sharp / Oxford University Press, 2010
• Answering critics — Byron Sharp / Ehrenberg-Bass Institute
• Identifying and prioritising Category Entry Points — Ehrenberg-Bass Institute
• Easy to Find: Being Where B2B Buying Happens — Magda Nenycz-Thiel & Jenni Romaniuk / Ehrenberg-Bass Institute, 2025
• Building Distinctive Brand Assets — Jenni Romaniuk / Oxford University Press, 2018
• Expert Perspectives: Jenni Romaniuk on Distinctive Assets — Contagious
• Prof Byron Sharp skewers Binet, tells marketers to sack agencies preaching share of voice — Mi3, republished by the Ehrenberg-Bass Institute, 2022