In the Yandex Advertising Network and ad exchanges, ads may be served through a process called behavioral targeting, which is when the served ads are tailored to the interest of users. By analyzing the behavior of users on the internet, in particular their search queries, Yandex selects the most relevant ad promotions for them. User interests are divided into short term and long term. If the user's preferences change, then the subject of the ad offer also changes.
Why is behavioral targeting useful?
Behavioral targeting allows you to serve ads to users who are actively interested in the advertised product or service. You can appeal to your target audience even on pages whose content does not match the subject of your ads. Statistics show that behavioral targeting generates in ad networks more than 80% of click throughs and conversions in all subjects where it can be used.
How data on user interests is collected
Yandex does not use behavioral targeting to serve ads of a personal nature (such as some aspects of medicine, dating).