Reach

Reach refers to the number of people who could potentially be exposed to a given ad. It is determined by how broadly or narrowly an advertiser defines their targeting criteria.

Wide targeting parameters — for example, all women residing in the USA — produce a large reach. Tightening those parameters — for example, women aged 20–25 living in Dublin, Ireland, who have expressed interest in running shoes — shrinks reach considerably. Advertisers can therefore control reach directly by adjusting the specificity of their audience targeting: broader criteria expand the addressable pool, while layering on demographic, geographic, or interest-based filters narrows it.