Facebook ads Lookalike audiences: Your how-to guide

If you’re looking to reach new customers with your Facebook ads, then Lookalike audiences offer a brilliant place to start. In this blog post, we’ll delve into what Lookalike audiences (LALs) are, how to create them, and why they are crucial for testing and optimising your Facebook ad campaigns.

Let’s explore together…

Understanding Lookalike audiences

Lookalike audiences (LALs) were first introduced to the Facebook advertising platform in 2013, and they are a brilliant targeting option to test with your Facebook ads.

Essentially, they allow you to find and target new customers who share similar characteristics, behaviours and interests with your existing customer base or a custom audience you’ve already created (warm audiences).

In addition to this ability to powerfully model a NEW audience on EXISTING customer data points, you can control the size and similarity of your lookalike audience by setting a percentage from 1 to 10% – more on this later.

Source audiences (custom audiences)

In order for an LAL to be effective, you need a data rich source audience to pull from.

Facebook or Meta as it’s now called, recommend your source audience to have between 1,000-5,000 people in it. But it is not just the size that matters – it is the quality of that audience that will make all the difference.

E.g: Using a source audience of email subscribers to create a LAL:

If your subscribers are unengaged and not really interested in buying, then the quality of your LAL will likely be poor in terms of buying behaviour.

To create a LAL, your source audience must contain at least 100 people in it from a single country. So if you only have 80 people following you on Instagram, you won’t be able to create a LAL of Instagram followers.

Why Lookalike Audiences Matter

Creating a high quality LAL holds immense potential for your Facebook advertising, and here’s why:

  1. Reaching High-Quality Prospects: By targeting users who resemble your current customers, you increase the chances of connecting with people who are genuinely interested in your products. This results in higher-quality traffic and more meaningful interactions.
  2. Expanding Your Reach: Lookalike audiences enable you to tap into untapped markets. As your business grows, it’s essential to explore new customer segments, and lookalike audiences make this process more efficient.
  3. Improved Conversion Rates: Since lookalike audiences comprise users with similar behaviors and preferences to your existing customers, they are more likely to convert. This can lead to improved ROI on your advertising campaigns.

Creating Lookalike Audiences: Step by Step

Let’s walk through the process of creating a lookalike audience for your ecommerce Facebook ads:

1. Start with a Source Audience

Your source audience serves as the foundation for your LAL audience. This can be a custom audience you’ve built from your website visitors, email list, purchasers or Facebook engagement. There are many different options but remember, the quality of your source audience directly impacts the effectiveness of your LAL audience.

Head to the ‘Audiences’ section in your Business Manager tools

At the top left, click the blue “Create Audience” button and select “Custom Audience.”

Start with building lots of different custom audiences. Include a custom audience of purchases, Facebook engagers, Instagram engagers and if you have an email list, a custom audience of your most engaged subscribers.

2. Create your Lookalike audience

Once you have created all your custom audiences, go back to the blue create button and click on ‘Lookalike audience’ (shown above) and you will see the below screen…

The first thing you will need to do is select a source. Meta prefers you select a value-based source (which I recommend), but it doesn’t need to be.

-> If you audiences are smaller with less events being fired (e.g the number of purchases being transacted through your website each week), you won’t be able to use this function.

If you can’t use a value-based source, then click on ‘other sources’ and type in your custom audience in the search bar. Select the one you want to test when it pops up.

3. Choosing the location of your LAL

After entering your LAL source, specify the location you want to target with your lookalike audience. You can choose a specific country, city, or region based on your business’s reach and goals.

3. Choosing the number of Lookalike audiences

Next, you’ll need to select the number of lookalike audiences that you want to create. We’re only going to create one, but you could create up to six at once if you wanted.

4. Choosing the size of your LAL

Next, you will need to choose the size of your audience.

When creating a lookalike audience, you’ll need to select a percentage that represents the size of the target audience compared to the source audience. A smaller percentage (e.g., 1%) results in a more precise match, while a larger percentage (e.g., 5%) offers a broader reach. Consider your campaign objectives and the available budget when deciding on the audience size.

I tend to test with a 1% first and if that doesn’t give me the desired results, I will expand that to a 1-3%. But every business is different, so make sure you test a variety of LALs to find your own sweet spot.

Once you’ve configured the audience parameters, click the “Create Audience” button. Facebook will then analyse its user base and generate a lookalike audience for your ad campaign.

Populating and Updating

Meta says it should take between 6 and 24 hours for your lookalike audience to populate. However, you can still use it for targeting as soon as you have created it. Your LAL audience will continue to update every three to seven days, as long as you’re actively using it.

Testing Lookalike Audiences

Now that you’ve created your Lookalike audience, it’s time to test its effectiveness. Remember, testing is crucial for refining your advertising strategy:

  1. A/B Testing: Create multiple ad sets, each targeting a different lookalike audience size or source audience. Compare their performance to identify the most successful combinations.
  2. Performance Metrics: Monitor key performance indicators (KPIs) such as CPM’s, click-through rates, conversion rates, and return on ad spend (ROAS) for each lookalike audience. This data will guide you in optimising your campaigns.
  3. Iterative Refinement: Regularly update and refine your lookalike audiences based on the insights gained from testing. As your business evolves, so should your targeting strategy.

Should you use Lookalike Audiences for your ad targeting?

Back when LAL audiences were first launched in 2013, they presented us with a huge opportunity to make our targeting of cold audiences (people who have never heard of your brand or businesses) more effective.

But in recent years (this year!) Meta have been making a big push towards broad targeting – where we are only showing our ads to people based on age, gender and location. There is no right or wrong way to do it, as always, it is all in the testing.

Always conduct your own experiments, to see what works for your brilliant business.


By effectively leveraging LAL audiences, you can reach high-potential prospects, increase your ad campaign’s efficiency, and ultimately help to drive more conversions. But remember, the quality of your custom audience will directly impact the success of your LAL.

So go ahead, experiment, refine, and find what works for you!

If you have any questions or would like to talk further about this, or Facebook ads your brilliant business, please send me a message on Instagram (I love to hang out there) or book a free call with me here.

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