Ask two competent marketers how to grow a brand and you may get answers that appear to be about different disciplines.
The first will talk about segmentation: divide the market by what people need and how they behave, choose the segments you can serve better than anyone, and build everything — product, price, message, channel — around them. Precision is the virtue. Serving everyone means serving no one.
The second will cite a body of empirical work, associated above all with the Ehrenberg-Bass Institute, showing that brands grow mainly by acquiring large numbers of light buyers, that the buyers of competing brands look statistically alike, and that the heavy loyalists on whom segmentation strategies concentrate are a small and largely unmovable minority. Reach is the virtue. Narrow targeting forfeits the growth.
Both positions are supported. Both are held by serious people. And the argument runs on because each side is answering a question the other is not asking.
Two different decisions
Segmentation is a decision about what to build and how to serve. Reach is a decision about whom to talk to. These are separable, and treating them as a single choice is what generates the false conflict.
A manufacturer of professional kitchen equipment has segmented meaningfully: restaurants are not households, and the product, warranty, distribution and sales model differ accordingly. Nothing in the reach literature suggests otherwise. What that literature does suggest is that, having decided to serve restaurants, the firm should try to be known by as many restaurants as possible rather than by a carefully chosen tenth of them.
Read this way, the propositions are complementary. Segment the market to decide what you are for. Reach broadly within that market to grow.
Where the disagreement is real
The complementarity is genuine but it is not complete, and it is worth being honest about the residue.
A real disagreement remains about message differentiation. The segmentation tradition holds that messages tuned to a segment's specific concerns will outperform general ones. The empirical tradition finds that distinctive brand assets — consistently applied to everybody — do more work than tailored propositions, because the binding constraint is being remembered at the moment of purchase, not being persuaded at the moment of exposure.
There is also a real disagreement about where the growth is. If most incremental revenue comes from light and occasional buyers, then loyalty programmes, retention campaigns and customer-lifetime-value optimisation are aimed at the part of the market with the least room to move. That is an uncomfortable finding for a great deal of installed marketing practice, and it has not been refuted by being ignored.
The test that settles it locally
Neither position is universally right, and the useful question is not which tradition to join but which conditions you are operating under. Three diagnostics do most of the work.
How different are the needs, really? If two groups want materially different things — different specification, different service, different risk — segmentation is describing reality. If they want the same thing and merely respond to different imagery, the segments are an artefact of the research instrument.
What limits your growth: relevance or memory? If prospects understand what you offer and choose otherwise, relevance is the constraint and precision helps. If most of the market cannot name you at all, memory is the constraint and reach helps. Most brands, most of the time, are in the second situation and believe they are in the first.
What does targeting actually cost you? Narrow targeting has an explicit price — the buyers you did not reach — and that price is rarely put on the slide next to the efficiency gain.
Why it matters more now
Digital media made narrow targeting cheap, easy and measurable, which pushed practice hard towards precision for reasons that had nothing to do with evidence about growth. The measurement favoured it, so the budget followed.
The same forces are now reversing: signal loss, privacy regulation and the collapse of third-party identifiers are making fine-grained targeting harder and more expensive at exactly the moment the evidence for broad reach has become difficult to dismiss. Firms that treated precision as a principle rather than as a temporary consequence of cheap data are discovering that they built a strategy on an affordance.