How remarketing works

This guide provides information on user lists and remarketing using the Ad Exchange remarketing tag. You can also use other Google products or real-time bidder to build and target user lists.

Policy requirement

If you're setting up a remarketing campaign and placing the remarketing tag on your site, you need to follow the Interest-Based Advertising Policy.

In order to participate in remarketing, you need to create at least one user list, which is simply a list of web visitors (cookie IDs) whom you would like to re-engage with a compelling message.

To do so, add the remarketing tag, a small snippet of code that you get from Ad Exchange, across all your site pages. Many sites have an identical footer for all pages, and this remarketing tag could be placed there.

Once you've added the remarketing tag to your site, you can create user lists for any of your webpages. For example, you could create a user list for visitors to your homepage. The remarketing tag tells Ad Exchange to save visitors to your "Homepage list." When people visit that page, their cookie ID is added to the remarketing list.


An online shopper is looking for new running shoes, so she goes to a to browse the different styles. However, she leaves without completing a purchase. Knowing that the shopper is a valuable potential buyer, could add the shopper to a "Shopper" list. This will enable to deliver an ad to this shopper and the other potential buyers on that list with a call-to-action that will encourage them to return to the website to complete a purchase.

How does remarketing work?

A pixel is embedded on your homepage (for example) - a pixel is a small, invisible piece of code that tells Ad Exchange to save visitors' cookies to your "Homepage" list. As people visit your homepage, their cookie is added to the user list. You can then create a campaign that targets messages only to visitors whose cookies are on this list. Your remarketing messages is not shown to people whose cookies are not on the "Homepage" list.

Once you've placed the remarketing tag on your site, you can begin to build your lists.

Broad versus narrow lists

Try to strike a balance between creating very detailed user lists and broader user lists. While detailed user lists let you further target your message, you'll get the most scale and volume with broader lists. Creating relevant and meaningful user lists is the primary key to success for remarketing. If you have questions, consult with your account manager.

Learn about cookies, tags, and rules


As people browse certain Google services and AdSense/Google Ad Manager publisher websites, Google stores a number in their browsers (using a "cookie") to remember their visits. This number uniquely identifies a web browser on a specific computer, not a person. Learn more about cookies.


A remarketing tag is a small snippet of code that you get from Ad Exchange that you can add to your website to start using remarketing. This tag auto detects whether or not the page on your site is secure (whether it starts with http or https), so there's no need to customize the tag based on the type of page you place it on.


Once you've added the remarketing tag to your site, you can define lists for different sections of your site using rules. For example, if you want to define a list for a page of your site where you sell electronics, you can use this rule: "URL contains electronics".

With rules, you can create as many lists as you want without having to add more tags to your sites.

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