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Audience Intelligence Glossary

What Is Regional Affinity?

Regional affinity describes where inside a country an audience is concentrated, measured against that region's share of the population. It answers a question that absolute audience counts systematically get wrong.

Why absolute regional counts mislead

An uncorrected map of where an audience lives shows the largest cities, every time, for every audience. That is a map of population, not of affinity, and it supports no decision — because every competitor's map looks identical.

Regional affinity = (region's share of the audience) ÷ (region's share of the national population)

A region with 4% of the population and 9% of the audience → index 2.25

Corrected this way, the map changes completely: mid-sized regions with genuine concentration surface, and large metropolitan areas frequently drop to around the baseline, because their audience share simply reflects their size.

What the corrected map is used for

  • Regional media allocation — spending in proportion to affinity rather than to population, which is what makes regional buying more efficient than national.
  • Out-of-home and retail siting — where physical presence meets an audience that is actually concentrated.
  • Sponsorship geography — checking whether a property's audience concentration matches the sponsor's distribution footprint, a mismatch that is invisible in national reach figures.
  • Expansion sequencing — which regions to enter first, based on latent demand rather than on size.

Reading it honestly

  • Small regions produce extreme values. A sparsely populated region can show a very high index on a small number of people. Read the index together with the absolute count.
  • Administrative borders are not audience borders. A catchment area crossing a state line appears as two moderate values rather than one strong one.
  • Affinity is not reachability. High regional affinity says the people are there, not that there is efficient media inventory to reach them.

How Rascasse builds it

Regional affinity is computed per country against that country's own population distribution, at regional level and, in the built-out markets, at postal-code level. Because the baseline is national, indices are comparable between entities within a market but never across markets — a 2.0x in Germany and a 2.0x in the United States are measured against different populations.

Live example

The regional map on Borussia Dortmund in Germany shows the corrected view: concentration, not population.

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