Ad retargeting is reaching out again with ads to people who have already visited your site or engaged with the brand but did not complete an action. It works as a reminder aimed at people who already know the brand, so it usually converts better and more cheaply than reaching new users. In practice the terms retargeting and remarketing are used interchangeably; where a distinction is drawn, retargeting tends to mean paid display ads to earlier visitors, while remarketing also covers contact by, say, email. (Compare: Remarketing, Dynamic Remarketing)