Audience expansion for YouTube

Audience expansion leverages Google’s machine learning technology to help scale and simplify how you optimize your YouTube Brand campaigns to find more people who are likely interested in your brand, product, or service.

Using audience expansion lets you drive brand awareness and influence consideration by finding audiences who are semantically like your chosen first-party audience list to help widen your reach.

Some of the benefits of using audience expansion are that it lets you:

  • Leverage machine learning technology: Find users semantically like your targeted first-party list using Google’s advanced machine learning technology.
  • Granular control: Narrow or expand how much reach you want to achieve depending on your campaign goals.
  • Scale your first-party data: Expand the scale of your first-party data.

Audience expansion is available for the following campaigns:

  • YouTube & partners on CTV
  • YouTube & partners video with product and brand consideration goals

For audience expansion on over-the-top streaming line items see Audience expansion for connected TV line items.

You can use the following eligible first-party lists:

Topics in this article

How audience expansion for YouTube works

Audience expansion models how it expands your potential reach to find people similar to your existing customers by using Google’s machine learning technology to understand general user behaviors and semantic trends in your anonymized first-party audience list. 

You can control how much you want to expand or narrow your potential reach to find the right balance between reach and finding relevant audiences to help meet your campaign’s goals. As you adjust the expansion, the pace of your spend is adjusted to expand your targeting to additional inventory that helps you reach audiences semantically like your first-party audience list if there’s enough budget and bids are high enough to support the adjustment.


How you use audience expansion and how much you expand or narrow your potential reach depends on your campaign goals:

Drive brand awareness and consideration

Audience expansion can help you maintain brand consideration for existing customers while driving brand awareness to relevant new customers who are more likely to be interested in your brand.

For example:

An advertiser wants to help a shoe company with an upcoming launch for a new line of shoes. They might want to drive brand awareness to new customers, while advertising to existing customers to maintain brand consideration. They could create a campaign that targets both their eligible first-party audience list and expanded audience to help meet their campaign goals. 


Before you use audience expansion for your YouTube campaigns, make sure you have the following requirements:

  • Your campaign must remain active: Your campaign must have already started or is scheduled to start within two weeks
  • For customer match lists: The list must have been uploaded or refreshed within the last 540 days to use audience expansion.
  • For tag-based remarketing lists: You must have more than 1000 YouTube users within the last 30 days to use audience expansion. Most lists contain both signed-in users and signed-out users.
Important: If you have less than 1000 YouTube users within the last 30 days, turning on audience expansion may cause your campaign to not spend.

To check the number of YouTube users for your tag-based remarketing list:

  1. Go to Audiencesand thenAll Audiencesand thenGeneral.
  2. Find your audience list under the Audience lists: Name column.
  3. For your audience list, check the YouTube users column. 
    Note: The total includes both YouTube users who are signed-in and signed-out.

Use audience expansion for YouTube

To turn on audience expansion for YouTube campaigns:  

  1. Go to a YouTube line item. 
  2. Under Ad group Targeting
  3. Select Turn on audience expansion for eligible first-party lists.
  4. Choose the amount of potential expansion using the slider: Least reach, moderate reach, or most reach.
  5. Choose one of the following:
    • Target expanded audience only: Selected by default. 
      • Excludes first-party audience lists and targets new audiences only.
      • For example: Consider this option when creating prospecting campaigns with brand awareness and consideration goals targeting new customers.
    • Target eligible first-party lists and expanded audience:
      • Includes both the first-party audience list and additional users from audience expansion 
      • For example: Consider this option when creating campaigns with goals of maintaining brand consideration for current customers while driving brand awareness with new customers.
  6. Select Apply when done.


You can create an offline report using the Optimized Targeting dimension to measure which impressions come from audience expansion and which come from your first-party list:

  • Yes: Impressions from audience expansion.
  • No: Impressions that don’t come from audience expansion and are from your first-party list.

Learn more in Dimensions in reports.


  • Audience expansion may take approximately 2-3 days from initial setup for the expansion to start serving.
  • Audience expansion doesn’t apply to instant reserve or programmatic guaranteed deals. 
  • Audience expansion can’t be used for:
    • Video ad sequencing
    • Target frequency
    • Exclusion targeting:
      • Audience expansion is only for inclusion targeting. 
      • You can only use the first-party audience list for exclusion targeting.

Frequently asked questions

What’s the difference between optimized targeting and audience expansion?

While optimized targeting and audience expansion both help you scale how you optimize your campaigns, they work differently and don't have the same limitations.

Here are key differences:

  Optimized targeting Audience expansion
How it works

Uses machine learning informed by real-time data from your campaign, such as clicks and conversions, to model how to find new audiences more likely to convert.

You can create a starting point for optimized targeting by adding targeting signals as hints to guide how it finds new audiences. 

Uses machine learning informed by your first-party data to find semantically similar audiences.

You use your first-party audience list as a model for how audience expansion finds new semantically similar audiences.

Control Less control over who you target. More granular control over how much reach you want to achieve.

Available for:

  • Display, video, and audio line items
  • YouTube video action campaigns

Available for:

  • YouTube product and consideration campaigns
  • YouTube & partners on CTV
Use Optimize how your campaign finds relevant people based on conversion data to drive awareness, consideration, or conversions. Optimize how your campaign expands to people who are similar to your target first-party audience list to drive awareness and consideration.




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