Social Advertising

Facebook Lookalike Audiences

Published February 2022

One woman in the foreground and similar women in the background

One woman in the foreground and similar women in the background

Lookalike audiences are a powerful tool in the modern marketer's repertoire. They are often used to expand existing audiences to new locations and products. However, their true potential is much broader and can help scale virtually anything.

With a Lookalike Audience, you can reach new people with your ads who are likely to be interested in your business because they share similar characteristics to your existing customers.

Lookalike audiences allow the social media algorithms to deliver ads to people who have similar characteristics to the people in your other audiences. This increase in audience liquidity gives the platform's algorithms more opportunities to find the best results for your desired campaign objective.

Learn more about Facebook advertising and why it’s still the best place for paid social here

    Editor's Info
  • You'll find our used sources at the end of each section.
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    Executive Summary
  • Lookalike audiences enables the algorithms to reach a broader set of people
  • With international lookalike audiences you can find people in new target countries
  • You can create lookalike audiences via your Pixel, SDK, or from offline data
  • Your required source audience should be high-quality
  • Facebook’s algorithm can dynamically enlarge your lookalike audience—if you want
  • Lookalike targeting is limited to young people under 18 in most countries

How a Lookalike Audience works

A lookalike audiences (LAL) is a way your ads can reach new people who are likely to be interested in your business, product, or service because they share similar characteristics to your existing customers. It uses an existing custom audience that you select for its source audience.

Image shows a lookalike audience.

Visualization of how a lookalike audience works

They work quite simple: take the top percentile of users who share the most common characteristics as your source audience. Choosing the top 1% results in a smaller but more homogeneous audience. Choosing a larger percentile, such as 5% or 10%, gives you a larger audience that is less homogeneous. We recommend a percentage between 1% and 3%, because the scattering loss is too high if you go beyond that.

Source Audience

The source audience, or seed audience, is the foundation of a lookalike audiences. Thus, it should be a high-quality audience to get well performing lookalike audiences. High-quality is when you use the most current data to match your ads with the right audience. Rather than use multiple sources, segment your audience and expand on good data sources. Choose a seed audience that directly relates to the objective you want to achieve. To increase online sales in a mobile app, use the SDK to generate a Custom Audience of your highest-value app users.

Meta recommends a size between 1.000 and 5.000 users in your source audience. Because if it’s to large the ad platform will have a difficult time finding users that match with everyone in the group, resulting in a less accurate lookalike audience. And you know that a less accurate audience can cause scattering loss and budget wastage.

Best practices for Lookalike Audiences

There are many best practices for creating lookalike audiences. These are often effective for one particular use case and less so for another. So, there is no clear standard solution that works for everyone. Rather, it’s important to align the lookalikes to the available data, metrics, and business goals.

Value-based Lookalike

You can create value-based Lookalike Audiences via your Pixel, SDK, from offline conversion data, or from your catalogue to find new high-value customers for your business. We can automatically create value-based Lookalike Audiences for you. To do this, we use the signals from these data sources as well as the values you provide to calculate the lifetime value of your customers and create new audiences. The created Audiences consist of people similar to your most valuable existing customers. You can create value-based Lookalike Audiences in the Ads Manager.

International Lookalike

You can also create international lookalike audiences. With international or cross-country lookalike audiences, companies looking to expand into new markets can find people in their target countries who are who are similar to their best customers. International lookalike audiences also enable you to optimize your advertising spend by allocating your budget to the countries where it will have the greatest impact. You can Create Lookalike Audiences in a desired country or countries, in a region, or in a trading area—such as EEA or NAFTA.

Targeting expansion

Enables the Facebook algorithms to reach a broader set of people than those defined in the detailed targeting section. You can use this option when you want to show your ads to additional people who their system determines might yield more results or a lower cost. Targeting expansion is specific to detailed targeting and doesn't apply to location, age or gender targeting options

Lookalike expansion

Enables the Facebook algorithms to reach a broader set of people than those you defined in your lookalike audience. Similar to targeting expansion, this option can help improve your campaign when their system determines you might obtain better results with an expanded audience.

Additional information for Lookalike

  • You need an existing source audience to create a Lookalike Audience
  • Your source audience must contain at least 100 people from a single country—but between 1.000 and 5.000 is recommended by Meta
  • You can create up to 500 Lookalike Audiences from a single source audience
  • Lookalike Audiences use your ad set locations and only include people from those locations
  • You can use lookalike expansion to show your ads to people outside your defined Lookalike Audience
  • People in your source audience are excluded from your Lookalike Audience
  • You can use multiple Lookalike Audiences at the same time for a single ad set. In this instance, the ad set targets your ads to people in any of your selected Lookalike Audiences

Lookalike targeting limitations

Since 23. August 2021, many targeting options such as detailed targeting, custom audiences, lookalike audiences, as well as saved audiences that include any of the above options are no longer available to target ads to young people under the age of 18 globally, 20 in Thailand or 21 in Indonesia. You can’t use detailed targeting to these age groups. However, you should read through the country-specific advertising guidelines of your chosen social media platform and follow the relevant points.

Learn more about targeting and targeting limitations here


If you want to reach a larger number of people than you have in your custom audience, you can add a lookalike audience. They are powerful in addition to your other audiences and complement your advertising strategy. But, they require a solid analysis of your current audiences, your strategy, and your main metrics. Ultimately, you must test the performance of your lookalike audiences to learn how to optimize and use them successfully.

We help our clients build working lookalike audiences to achieve their business goals in the most efficient way. Contact us to find out if we can help you too.

Thank you for reading and have a nice day!