Most volume lives in the long tail — the Dove case

Nearly 50% of category buyers didn't shop Dove in six years. Of those who did, over 80% bought fewer than once a year — and those light buyers accounted for 50% of all Dove sales. This is the shape marketing strategies get backwards when they optimise for the loyal heavy user who is visible in the data instead of the light buyer who is invisible but numerous.
Indicative curve. Bar heights approximate the Kantar Worldpanel Dove distribution as published in the Ehrenberg-Bass teaching materials. Exact shape varies by category — but the pattern (steep drop, long tail, majority of volume in the tail) holds across beer, cars, insurance, software, banking, and every FMCG category the NBD-Dirichlet has been fitted against.
Sources: Kantar Worldpanel — Dove long-term buyer behaviour, 6-year panel; Ehrenberg & Goodhardt — the underlying NBD-Dirichlet repeat-buying framework; Sharp, How Brands Grow (2010) — the "light buyer paradox" formulation; Romaniuk & Sharp, How Brands Grow Part 2 (2016) — cross-category replications.