Typically, to use display retargeting you must first upload a pixel and pass it in the URL parameter in the ad code.

The next step is to place that code on your site or app where users can see it. This way, when you know someone has visited your website, but did not convert, you can target them with an ad on another website they visit later.

Since this process starts by placing pixel tracking code on webpages so marketers can track which users visited specific pages and how long they spent there, identifying valuable pages is key. You need to identify which pages keep people around and which drive conversions so you only target users who have shown interest in buying through behaviors like login activity and time spent well below the fold. Once you know which pages you want to target, users who visited those pages will be retargeted on other sites they visit after leaving your site.

Advertisers can also make use of landing page pixel tracking tags for this purpose as well if more accurate targeting is desired.