Create Audiences with Mailerfind in Meta Ads
In this article, we explain how to leverage the data extracted by Mailerfind to create custom and lookalike audiences in Meta Ads. Custom audiences allow you to directly target the users you have obtained through Mailerfind—for example, the followers of an Instagram account—so that those users will see your ads. On the other hand, lookalike audiences are generated from the custom audience and enable you to expand your reach to users who share characteristics with your original base.
Initially, we recommend targeting the custom audience to evaluate performance without saturating the original audience. Once the campaign is proven successful, you can broaden your reach by employing a lookalike audience, which prevents overexposure of the already-targeted users and enables you to capture new potential customers.
Export Data from Mailerfind
Log in to your Mailerfind account and export the dataset in CSV format. This file includes both email addresses and phone numbers extracted from Instagram followers.

Access Meta Ads Manager
Log in to Meta Ads and navigate to the " Audiences" section within Ads Manager.

Create a Custom Audience
Select the "Create Audience" option and choose " Custom Audience".

Select Customer List
Next, choose the " Customer List" option.


Upload the Audience
Click on "Choose a file from your device" or drag the CSV file you just downloaded. Then, enter a descriptive name for this audience; we recommend using the same name as in Mailerfind.

Assign the Identifiers
Ensure you assign the identifiers as shown in the image. By default, the configuration is already correct, but it is important to verify.


Mailerfind extracts both email addresses and phone numbers from Instagram followers, enabling you to create more precise audiences.
When uploading the file in Meta Ads, you will need to map the fields from Mailerfind to those required by Meta. Select email for email addresses and full_phone_number for phone numbers.
No, Mailerfind automatically cleans and purges the data, ensuring that it is in the proper format for use in Meta Ads.
The ideal percentage will depend on your objectives. A lower percentage (1-2%) creates an audience very similar to your original base, ideal for specific conversions, while a higher percentage expands reach but may reduce similarity. Experimentation is key to finding the right balance.
Initially, we recommend targeting the custom audience to evaluate performance without saturating the original audience. Once the campaign is proven successful, you can broaden your reach by employing a lookalike audience, which prevents overexposure of the already-targeted users and enables you to capture new potential customers.
Steps to Create Audiences with Mailerfind in Meta Ads
Export Data from Mailerfind
Log in to your Mailerfind account and export the dataset in CSV format. This file includes both email addresses and phone numbers extracted from Instagram followers.

Access Meta Ads Manager
Log in to Meta Ads and navigate to the " Audiences" section within Ads Manager.

Create a Custom Audience
Select the "Create Audience" option and choose " Custom Audience".

Select Customer List
Next, choose the " Customer List" option.


Upload the Audience
Click on "Choose a file from your device" or drag the CSV file you just downloaded. Then, enter a descriptive name for this audience; we recommend using the same name as in Mailerfind.

Assign the Identifiers
Ensure you assign the identifiers as shown in the image. By default, the configuration is already correct, but it is important to verify.


Frequently Asked Questions
What data does Mailerfind extract?
Mailerfind extracts both email addresses and phone numbers from Instagram followers, enabling you to create more precise audiences.
How do I map the fields when uploading the CSV?
When uploading the file in Meta Ads, you will need to map the fields from Mailerfind to those required by Meta. Select email for email addresses and full_phone_number for phone numbers.
Is it necessary to manually clean or purge the data?
No, Mailerfind automatically cleans and purges the data, ensuring that it is in the proper format for use in Meta Ads.
What similarity percentage is recommended for a lookalike audience?
The ideal percentage will depend on your objectives. A lower percentage (1-2%) creates an audience very similar to your original base, ideal for specific conversions, while a higher percentage expands reach but may reduce similarity. Experimentation is key to finding the right balance.
Updated on: 09/03/2025
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