Why Household Penetration Beats Loyalty for FMCG Brands

By Fardeed · July 2026 · 7 min read

When sales slow down, the instinct in most FMCG marketing teams is the same. Build a loyalty scheme. Reward the best customers. Give the top 20% a reason to stay.

It feels like the responsible thing to do. It is also, according to several decades of marketing science, not where growth comes from.

The clearest predictor of whether a brand grows is not how loyal its existing buyers are. It is how many new buyers it adds. That finding has a name, a body of evidence behind it, and a direct implication for where a marketing budget should go.

What Actually Predicts Growth

A brand's growth is explained almost entirely by how many people buy it, not by how often its existing buyers come back. This is one of the most tested findings in marketing science, replicated across categories, countries, and decades by the Ehrenberg-Bass Institute, the marketing research centre backed by Coca-Cola, P&G, Mars, and Nielsen.

The mechanism behind it is called the Double Jeopardy Law. Smaller brands are punished twice. They have fewer buyers, and the buyers they do have are slightly less loyal on average than the buyers of bigger brands. That second part is a consequence, not a cause. Loyalty rises because a brand has more buyers, more visibility, and more purchase occasions. It does not work in reverse. A brand cannot build loyalty first and expect market share to follow.

This is uncomfortable for a marketing team under pressure to show results quickly. A loyalty campaign is easy to launch and easy to report on. A programme built to reach new buyers is harder to target and slower to show up in a dashboard. But the evidence points in one direction. If the goal is growth, the campaign has to be built around reach, not retention.

The 80/20 Rule Is Mostly Wrong

Most marketing teams have internalised some version of the 80/20 rule: 20% of buyers generate 80% of sales, so that 20% is where the value sits. The real ratio, tested repeatedly across FMCG categories, is closer to 50/20. The top 20% of buyers account for roughly half of sales. The other half comes from everyone else: light buyers, occasional buyers, people who buy the category but not necessarily the brand.

That other half is not a rounding error. It is the difference between a brand that grows and one that plateaus.

There is a second piece of evidence that makes this sharper. Roughly 30% of Coca-Cola's buyers in any given year do not buy a single can of Coke (Ehrenberg-Bass Institute). Coca-Cola is arguably the most recognised brand on the planet, and even it depends on light and lapsed buyers cycling in and out. The Law of Buyer Moderation shows the same pattern at every brand size: heavy buyers in one period tend to buy less in the next. Today's light buyer is tomorrow's heavy buyer, and a strategy built exclusively around today's heaviest buyers misses the people who will actually carry the brand forward.

What we find: The brands most anxious about loyalty are often the ones with the least reason to be. A shrinking or flat brand loses buyers from the top and bottom of its customer base at the same time, and no retention programme fixes the top of the funnel. The fix is always the same: get more people to try the product in the first place.

What Loyalty Programmes Actually Do

A loyalty scheme is not without value. It can lift the frequency of an already engaged customer and it can be a useful data-capture mechanic. What it does not do, on its own, is grow a brand.

The reason is straightforward. A loyalty programme, almost by definition, reaches people who are already buying. The points, the tenth-coffee-free card, the app with a running balance, all of it is aimed at someone who has already chosen the brand. It is optimising a relationship that already exists rather than creating a new one.

Price promotions carry a related problem from a different angle. A temporary price cut moves units, but it disproportionately rewards people who were going to buy anyway, and it trains the remaining buyers to wait for the next discount. A brand selling at a 30% margin that cuts price by 10% needs to sell roughly 50% more units just to stand still. None of that volume is guaranteed to be a new household. Retailers see this in their own promotional data constantly: the same names redeeming the same deals, quarter after quarter.

None of this means loyalty and promotions are wrong to run. It means they are solving a different problem than growth. Confusing the two is where marketing budgets get misallocated.

The Shelf Is Getting More Competitive, Not Less

The pressure to win new buyers, rather than simply protect existing ones, is getting sharper. Private label products now hold 38.1% of the European grocery market by value and 46% by unit sales (NielsenIQ, 2024), and in ten European countries private label share now exceeds 30%. Retailers are not shy about backing their own-label ranges with the best shelf positions, and every household that defaults to the retailer's own brand is a household a manufacturer brand has to win back from a standing start, not retain. This is why new product launches and trial-driving activity carry so much weight in a penetration strategy.

A brand that spends its growth budget exclusively defending its existing buyer base is, in effect, ceding the fight for new households to whichever competitor, branded or private label, is actually investing in trial. Penetration is not just the theoretically correct growth lever. It is the one that determines who wins shelf space over the next five years.

What Penetration-Led Growth Looks Like in Practice

Reaching new buyers sounds simple and is operationally difficult. Retail shoppers are on autopilot: they walk the same aisles and reach for the same products without much conscious thought, which is exactly why a new or challenger brand struggles to interrupt that pattern. The marketing that reaches a non-buyer, a paid social ad, an influencer post, a sampling stand, is easy to run. Proving that it actually created a new buyer, rather than an impression, is the harder problem, and it is the reason so many brands default back to loyalty spend they can measure more easily.

This is also where a mechanic like receipt-verified cashback attached to a launch earns its place in the conversation. It gives the brand a concrete, verified count of new-to-brand buyers rather than an estimate, which is the piece of evidence a penetration strategy is otherwise missing. The point is not the mechanic itself. The point is that whatever tool a brand uses to chase penetration needs to answer one specific question afterwards: how many of these buyers were new? For a walk-through of how that count is produced, see how SeeGap works.

The Only Way to Grow Is to Get More Buyers

None of this is a new discovery. Byron Sharp published the core argument in How Brands Grow in 2010, and the Ehrenberg-Bass Institute has continued testing it in category after category since. The finding survives because it keeps being true, not because it is fashionable.

A loyalty scheme can be a sensible part of a marketing plan. It is not a growth plan. If the objective is growth, the question worth asking in the next budget meeting is not how to reward the top 20%. It is how many new households the brand reached last quarter, and how many of them will still be buying next quarter.

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