Contextual advertising
Contextual advertising chooses where to show an ad based on the content being viewed (the topic of the page, the video or the app) rather than on the person’s history.
It is the oldest principle in advertising: selling climbing gear in a climbing magazine. Online, the platform analyses the text, images or audio of each page before bidding and classifies it by topic, usually with the IAB Tech Lab content taxonomy. The advertiser buys categories (recipes, cars, personal finance) or keywords, and excludes those that do not suit it.
It came back to the fore with the decline of third-party cookies, because it needs no personal data to target. Its limitation is that it gets the moment right, but not necessarily the person: someone reading a film review may never go to the cinema. That is why it works best combined with quality audiences, with context choosing the setting and the audience choosing who.
