Google Remarketing
Google Remarketing lets you show ads to people who have visited your website or used your mobile app before. When people leave your website without buying anything, for example, remarketing helps you reconnect with them by showing relevant ads of your company as they browse the web, as they use mobile apps, or as they search on Google.
Remarketing: Your goal is simple. Gives past visitor that second chance by bringing them back to your site to convert.