To create an Audience of users who have previously visited your website for remarketing purposes, you must first create a segment pixel and place it on the Advertiser’s website. For more information on creating this pixel see here: Segment Pixels.

Once created and placed, the remarketing pixel will fire when a user lands on the page and store that User’s ID in an Audience segment. This Audience can then be associated to a Line Item. By associating this Audience to a Line Item, ads will serve on the web only to users who have visited the webpage where the pixel is placed.

The segment pixel can also be associated to a Creative during the Creative upload process. This will cause the pixel to fire and add a user to the Audience segment when they are served the Creative, even if they do not click on the ad or land on the webpage.