Targeted advertising

Targeted advertising is when a social media platform uses the data it holds about you to decide which advert you see. The platform is not choosing adverts at random: it matches each advert to users whose details and interests fit what the advertiser asked for.

When an organisation sets up a paid advert, it can choose factors such as gender, age, location and interests. For example, a company selling revision planners might target 14- to 16-year-olds in Manchester who follow study or homework accounts. The platform compares those choices with the profile data it stores, such as your age, town and the pages you like, and shows the advert only to users who match.

Third-party cookies add to this picture. These are small files placed by a company other than the website you are visiting, and they record pages you view across different websites. If you spend time reading about camping tents on an outdoor shop's site, a third-party cookie can pass that interest to an advertising platform, which may later show you adverts for sleeping bags. Your browsing outside the platform can therefore shape the adverts you see inside it, and it helps the platform build a picture of what you like.

Because the data is different for each person, different users receive different adverts, and each advert is more relevant to that user's age and interests.

This is the aim of targeted marketing: to put an advert in front of the people most likely to want the product, rather than paying to show it to everyone. It also shows how personal and business activity can blur. Your personal posts, likes and browsing create the data that businesses use to aim adverts at you, so using social media for fun affects what commercial messages you receive.