How to set up ads to be shown to a user who previously visited the site?

Question

contextual advertising

What is the name and through which service is advertising configured if the user has previously visited the site. For example, a site with a repair service has contextual advertising set up, but some users leave the site and do not immediately order. Is it effective to show such banners to those who have previously visited and were interested in how to implement it? And your recommendations.

Answer 1

This type of advertising is called retargeting (remarketing on Google). It is configured by creating an audience in the system. For example, in Yandex, on the campaign page at the bottom there is a link to the audience.
It is effective if your user does not make a purchase decision immediately.