With a Lookalike Audience, you can create an audience that closely matches your target audience in real life. This lets you target ads based on demographic data to reach people who are more likely to be interested in your goods or services.

Lookalike Audiences are based on an existing source audience. Types of source audience include existing Custom Audiences, page fans, or conversions.

For example, let’s say you have a Custom Audience for people likely to buy horse and riding equipment; we’ll call this Horse Owners. Based on this audience, you can now proceed to create Lookalike Audiences for each country that your campaign targets: Horse Owners Germany, Horse Owners Philippines, Horse Owners Peru…

The result is that your campaign reaches the screens of audiences in Germany, the Philippines, and Peru who look most like your original Custom Audience, Horse Owners.

Note that Facebook is gradually deprecating the targeting of Lookalike Audiences by country.

Shaping your Lookalike Audience

Choosing the source audience

When you create a Lookalike Audience, select a source audience that is selective toward the kind of people you want to reach with your campaign.

The more common attributes or shared characteristics the people in the source audience have, the better the people in the Lookalike audience will match to those attributes and characteristics.

For example, a generic Website Custom Audiences of all website visitors is not a good source for your Lookalike Audience. Instead, create Lookalike Audiences from source audiences based on the people who are visiting specific pages or areas of your website or people performing specific actions.

As a rule of thumb, a source audience of about 5,000–15,000 people works for regular Lookalikes. For value-based Lookalikes, as long as the user values provided are accurate, you should use as large a source audience as possible.

Facebook will always try to create a Lookalike using the people from the same country as the target country. If this results in a Lookalike Audience smaller than 100 people, then another country will be used for sourcing. Currently, there's no way to choose which other country is used. 

Your source audience needs to have at least 100 people from a single country. This is true even if the source contains people from several different countries. 

Choosing the percentage range

The percentage range of a Lookalike Audience defines what percentage of the people most similar to your target audience who are on Facebook and who live in the target country will be included in the audience to be generated.

For example, creating a 1% Lookalike for Germany would generate a targetable audience that contains 1% of people on Facebook in Germany who are most similar to the people in your source audience.

If your Lookalike Audience is small, it closely matches an existing audience, which means it’s most likely to generate clicks from a larger percentage of those who see the ad. However, that means that fewer people in total will in fact see the ad. 

In a nutshell, smaller percentage Lookalikes will be closer matches to your source audience. Larger percentage Lookalikes will allow reaching a broader user base.

The smaller the Lookalike, the more closely the people in Lookalike will be to the people in the source audience. This is why small Lookalikes usually bring better results, assuming the type of source audience is right, and if there is enough volume for your purposes.

If the results are good with small 1-2% Lookalikes and you want to get more volume, you can test larger Lookalikes, e.g., 4-5% to see if you can still sustain good enough results with those while getting more volume.

We recommend testing with 1% or 2% Lookalikes first to see if these yield good results. If the number of people in a 1% Lookalike for a given country looks too small, then test with a 2% Lookalike. 

Create a Lookalike Audience

Note: Lookalikes update automatically roughly every 3-7 days if the audience is in active use in a campaign.

1. On the three-dot menu, click Account Library > Custom Audiences.
2. Click Create Lookalike.
   
   
   
   
3. Type a descriptive name for the audience.
   We recommend creating naming conventions that provide enough information about the Lookalike without users having to separately view each one.
4. Select the source audience:
   • Custom Audience
   • Page Fans
   • Campaign Conversions

   Note Use the same ad account to create the Lookalike Audience that was used to create the source audience. Lookalike Audiences cannot be created from a shared audience. However, you can share Lookalike Audiences between ad accounts, if it is whitelisted on Facebook. The Lookalike Audience is updated automatically on both accounts using it.

5. Under Select target countries, enter the countries where you want to use the Lookalike audience for targeting.
   • Create a Lookalike Audience for use in multiple countries: select all the target countries.
   • Create a separate Lookalike Audience for each country: select the Create a new audience for each country check box.

   Facebook always tries to use the same country as the source to populate the Lookalike. However, if the resulting source audience would have fewer than 100 people, the Lookalike Audience is populated with people from another country. This allows expansion to new geographical markets with Lookalikes before a local source audience exists.

   Note Currently, there's no way to choose which other country is used. The source country is only displayed once the Lookalike has populated.

   You can also use existing country bundles by clicking Bundles. This is helpful if you have long lists of countries that you'd like to include in your audience, or if you tend to create multiple audiences utilizing the same sets of countries.

6. Under Lookalike Audience sizes, choose one or more percentage range(s).
   Lookalikes can be created up to 20 % of the audience in the source country.
   Select multiple percentages and countries to create several audiences at once.
7. Click Create lookalike.

Once created, Lookalike Audiences can take 1-6 hours to be fully populated.

While the audience is populating, [create the ad sets] that target the new Lookalike Audience.

Once the Lookalike Audience is ready, delivery to the people included will catch up and work as normal.

Create Lookalikes from Custom Audiences and Website Custom Audiences (WCA)

You can use your current Custom Audiences as a source for the Lookalike Audiences. These include both Custom Audiences and Website Custom Audiences.

1. Click the Custom Audience radio button.
2. 2. Open the Custom Audience drop-down menu to select or search for a Custom Audience or WCA.

Create Lookalikes from page fans

You can create Lookalikes Audiences from people who are fans of a Facebook page.

1. Click the Page Fans radio button.
2. Select a page on the drop down menu.

Create Lookalikes from campaign conversions

You can create Lookalike Audiences from campaign conversions (based on Adset Based Conversion Lookalikes (ABC LAL); see below).

This selection can find a new audience of users that are similar to the users that converted in a previous campaign. This is useful for leveraging existing conversion data in the wake of a particularly successful campaign.

Another good use case is for launching a campaign in a new country where you don’t have any user data yet, but do have lots of conversions from a previous campaign.

1. Click the Campaign Conversions radio button.
2. Select a campaign on the drop-down list.

The list shows all your campaigns, sorted by the number of conversions. For each campaign you can see the campaign objective (Conversions, Product Catalog Sales, Link Clicks, etc.) and the number of conversions.

The campaign must have at least 100 conversions to be used as a Lookalike source audience. We recommend using a campaign with more than 200 conversions for better performance.

You can search for campaigns by name or by Facebook ID.

Create Lookalikes from ad set conversions (ABC LAL)

You can also create Lookalike Audiences using conversions from smaller ad sets in a campaign. These are called Adset Based Conversion Lookalikes, or ABC LAL.

The difference between creating a Lookalike Audience from ad sets versus total campaign conversions is that if you have enough conversions, you can select just the best performing ad set and leave out sets with poorer performance.

The ad set must have at least 100 conversions to be used as a Lookalike source audience. We recommend using a set with more than 200 conversions for better performance.

1. Go to the Ad Sets list view.
2. Select the sets on the list.
3. Click More and then click Create Lookalike Audience on the drop-down menu.

FAQ

My lookalike won't populate. What's wrong?

First check that the source audience has at least 100 people.

If the Lookalike source source, % ratio and country are identical to an existing Lookalike Audience, Facebook won't populate the new Lookalike Audience. If this is the case, use the original Lookalike Audience instead.

If neither of these is the issue, contact Smartly.io support to check that the source audience is valid and ready to use.

I cannot create Lookalikes bigger than 10% on Ads Manager, why?

15% and 20% Lookalike audience creation are unique to the Smartly.io API.

How can I find out the source audience used for my Lookalike audience?

Go to Library > Custom Audiences and find the Lookalike entry.