Glossary A–ZLetter A
Audience measurement
Audience measurement determines how many people are within view of an advertising medium or facing it, and derives impressions and reach from this.
It is the basis for prices that refer to impressions. Methods range from manual counts and sensors to extrapolations from mobile device movement data.
At a screen in a railway station, for example, passers-by can be counted, the figure can be derived from passenger data, or sensors can record anonymously how many people look towards the screen. This produces a number of impressions per hour, which is combined with the schedule to give impressions per ad play. For the advertising market, what matters is that different networks measure according to comparable rules.
Operators should disclose how their figures are produced and how old they are. Cameras and sensors are sensitive under data protection law; they need a legal basis and careful assessment under the GDPR as soon as individuals could become identifiable. Measurement answers how many people were nearby, not whether they noticed or remembered the advert.