The term "behavioural targeting" refers to a widespread practice in the field of online marketing and advertising. It is a strategy in which the behaviour of internet users on the internet is tracked in order to display targeted advertising and content to them. This is done by analysing data such as search queries, click behaviour, websites visited and demographic information.

Essentially, behavioural targeting aims to adapt personalised advertising messages to the individual interests and preferences of users. By analysing a user's online behaviour over a period of time, it can make predictions about what type of content or products that user is likely to find appealing. This enables companies to organise their advertising measures more efficiently and address their target group more precisely.

This method has both positive and negative aspects. On the positive side, users can benefit from more relevant content and products that better match their interests. This can improve the overall user experience. In turn, companies can benefit from a higher conversion rate and more effective marketing campaigns.

On the negative side, however, there are also privacy concerns. The fact that users' online behaviour is tracked to create profiles has led to privacy concerns in the past. Some people are concerned about their personal data being collected and used without their explicit consent.

In recent years, various rules and regulations have been introduced to protect consumers' data protection rights, such as the General Data Protection Regulation (GDPR) in the European Union. These laws require companies to be more transparent about how they collect data and how they use it. Users also have the right to object to their behaviour being tracked online.

Overall, behavioural targeting is a controversial practice that has changed the way companies advertise and how users experience the internet. It is an important part of the Attention Economy, in which companies compete for the attention of consumers.