Reach in advertising refers to the total number of different people or households exposed, at least once, to a medium during a given period). It is a measurement of the size of the audience that has seen an ad or campaign content. Reach should not be confused with the number of people who will actually be exposed to and consume the advertising, though. It is just the number of people who are exposed to the medium and therefore have an opportunity to see or hear the ad or commercial).
Reach may be stated either as an absolute number or as a fraction of a given population). For example, it can refer to specific audience segments or to a broader percentage of the population. Reach does not increase with subsequent exposures to the same viewer, which is instead referred to as frequency.
Effective reach is a term used to describe the quality of exposure, and it refers to intentionally targeting viewers most likely to convert into customers, who want to engage or take action. However, reach measurement refers to the pure quantity of reach and does not consider the effectiveness of the ad on the consumer.
To calculate reach in advertising, the formula is Reach = Impressions/Frequency, which is an average of the gross reach over the course of the life of an ad.
