About similar segments for Search

Remarketing allows you to reach people who have already visited your site and connect with an audience that's already interested in your products or services. You probably also want to find new visitors for your site, which you can do by finding people who have similar search behavior to your existing remarketing list members.

If you use Customer Match, using similar segments may benefit you to help expand the reach of your lists to more users for the purpose of new customer acquisition or expansion of your advertising campaigns.

As Apple’s App Tracking Transparency (ATT) policies go into effect, your data segments (especially website, app and automatically created segments) and Customer Match segments may be impacted on iOS 14 traffic (including the use of these segments for exclusions). Campaigns promoting web-based conversion goals - particularly those using Customer Match and your other data segments - may also find performance fluctuations. During this time we will be expanding modeled conversions to more iOS 14 traffic.


  • Find and target people similar to your site’s visitors
  • Simplify finding audiences to target
  • Get new potential customers

How it works

Google Ads looks at the recent search activity of the visitors in your remarketing list to help aggregate search behavior of the visitors in your list. Based on this information, the system automatically finds new potential customers whose search behavior is similar to that of people in your remarketing list.

Say you've created a remarketing list of people who bought running shoes from your sporting goods site. Instead of helping you reach broad groups of people interested in "running", similar segments will identify that people on this list tended to search for "triathlon training" and "buy lightweight running shoes" before coming to your site and making a purchase. Based on this, similar segments will then find other people with similar search behavior, such as people who searched for "buy lightweight running shoes".

Your similar segments lists will automatically get updated as the original list evolves and people change their search activity. So, you don't need to update the similar segment list after it gets created.

Qualifying for similar segments

To find similar segments, Google Ads looks at the millions of people searching on Google. The system will automatically identify which of your remarketing lists qualify for similar segments based on a variety of factors, including but not limited to the following:

  • The number of visitors on the original list
  • How recently these people joined the original list
  • The similarity of these visitors’ search behavior
  • Any adjustments made to the original list

A similar segments list is created from a remarketing list or Customer Match list with at least 1,000 cookies with enough similarity in search behavior to create a corresponding similar segment. Learn more about how Google Ads collects user information

Website tag and rule-based remarketing lists, as well as Customer Match lists built from email addresses, mailing addresses, and/or phone numbers, can be used to generate similar segments. If these sources don't have enough information, you may have to wait for more interactions and search activities. In these cases, the list may appear as "Incompatible" in the Shared Library's Audience manager.

Keep in mind

Similar segments do not use sensitive information, such as search activities based on race, religion, sexual orientation, or health. Learn more about our Personalized advertising policy

People who don't want to be included in similar segments are able to opt out through their Ads Settings.

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