Meta Custom Audiences guide: how to create and automate

Marketers are using Facebook Custom Audiences to improve their marketing campaigns and conversion rates. Here are the key use cases of custom audiences:

• High-intent users retargeting. As an example, you can create an audience filled with data on users who added to cart in the last 7–14 days, but didn't purchase. Retargeting such "warm audiences" usually leads to increased conversions.
• Customer retention & upselling campaigns. The existing customers are typically the most profitable audience for the business. After the purchase, you can retarget the customers with the products or services related to the one they bought.
• Engagement-based nurturing. Some users who interact with your ad aren't ready to buy the product. For example, you can use engagement custom audiences for users who watched 50% or 75% of your brand video on Meta and retarget them with a more sales-focused ad campaign.
• Precision targeting by lifecycle stage. Also, you can set up to avoid targeting a specific audience while running the campaigns. For example, if you are running a "research stage" ad campaign, you can exclude users who have already added an item to a cart. This prevents redundant targeting and ensures high-intent leads aren't annoyed by irrelevant ads.

Creating a Facebook Custom Audience includes selecting a source, such as website traffic or customer lists, and specifying audience rules in Meta Ads Manager. This section is aimed at helping you select the one that fits your needs. Meta divides Custom Audience types into two groups: 

• Your sources - data you own and control. It works for businesses that have their own website, and interacting with Meta ads is one of the touches on the website visitors' journey. Opting for "Your sources" can show the whole customer journey and supply the necessary data to Meta for audience targeting.
• Meta sources - activity that happens on Meta's end. These types of sources will be helpful for smaller businesses that have no website and use Meta Shops (check out option within Meta) or lead forms running Facebook Lead Ads.

We will focus on the "Your sources" options comparison as they are more complex and popular among marketers. You have a choice among five options:

The data accuracy and maintenance highly depend on the implementation method. Server-side tracking is a helpful technology to achieve precise data, as it firstly sends data to sGTM, which is hosted in a cloud server, and only then to the analytics services you use. The cloud server becomes a proxy between a website (or another data source) and external tracking tools like Meta. In this way, the data becomes less affected by ad blockers and browser restrictions, allowing you to achieve 15%-30% more complete data in Meta Events Manager.

As for the "Your sources" data collection automation, there are also tools that allow you make it easier - configure them once, and they update Meta Custom Audiences automatically. In this article, we focus on such an auto-update configuration. The setup of server-side tracking for Meta is more complex than client-side, but in the long run, it allows you to automate the data flows and improve audience targeting.

For the purpose of this article, we will focus on creating a customer list custom audience, as it:

• Uses first-party data that won't be blocked while transferring. Client-side tracking (the Meta Pixel) is often blocked by adblockers or browser restrictions. Since you send customer identifiers (like email or phone) directly to Meta, no browser or operating system can "block" the data transfer.
• Provides high match quality and accuracy. Instead of Meta figuring out who a visitor is based on their IP address or cookies, you are providing a direct match with first-party data. Using a server-side sync allows you to send identifiers (email or first and last name), which can improve your Event Match Quality (EMQ) score.
• Allows easy automation of first-party data sending to Meta. If configured with Stape's server GTM tag, you don't need to figure out Meta's guidelines on CSV files and manually upload CSV files every week; your Meta audiences remain updated 24/7. You can configure this setup even if you aren't using Stape (explain in detail below).

But if you select other sources, extend the collapse element below to see what solutions can help you improve the quality of the data you collect and automate the Custom Audiences setup: 

The section will focus on improving data quality and automation of data sending if you select Website/App activity or Offline activity while configuring Custom Audiences in Meta.

1.1 Open your Meta Ads Manager, click "All Tools" and navigate to the "Audiences" section.

1.2 Create a new custom audience. To do it, click Create audience button.

1.3 Select "Customer List" on the next step.

Stape's Meta Custom Audiences tag, which we will configure in the following steps, is designed to interact with Meta’s Marketing API to automatically add or remove users from a customer list.

Unlike website-based audiences that rely on cookies and expire after a set time (e.g., 30-180 days), a Customer List audience is persistent. Once a user is added via the Stape tag, they stay in that audience until you remove them.

1.4 On the next screen, you may be asked to add your Ad Account to a Business. Be sure to select the Ad Account that belongs to the Business Manager where you will create the System User, if you don’t use Stape (below, we explain in detail whether you need to create a System User and how to do it).

1.5 In the next step, Meta provides formatting guidelines for the CSV file. You should prepare the file and regularly update it. But if you configure automatic data sending to Meta, you can skip preparing the file. In the following steps, we show a workaround to configure the audience.

1.6 Click on the tab "Paste comma-separated values" and add some dummy data, like your email. Sometimes, this field may not work. If you encounter such a problem, click the "Upload a file" tab and upload this CSV file. The file contains an example with correct formatting.

1.7 Click "Import and create" and in the very end click "Done".

To complete the setup, you will need to have:

• Configured server GTM container.

• Configured data sending from the web to the server GTM container. You can set it up using server-side Google Analytics 4 or Data Tag/Data Client.

You must choose and configure one of the following authentication methods:

• Use Stape’s connection (recommended) - the easiest option. Just enable the Meta Connection in your Stape admin account.
• Use your own Meta credentials - select this option if you’re not using Stape’s services or are on a free Stape plan.

If you go with Meta Connection by Stape, you can use our CRM apps (at no charge). In this case, you should opt for the Meta Custom Audience connection method within the app, and you don’t need to configure the tag in sGTM as we describe below.

Currently, we have the integration available in the following apps:

• Configure Zoho CRM
• Configure HighLevel CRM
• Configure Pipedrive CRM
• Configure HubSpot CRM
• Configure Salesforce CRM
• Configure Odoo CRM
• Configure Klaviyo CRM
• Configure ActiveCampaign CRM 

4.1 Add the Meta/Facebook Custom Audience tag to your workspace.

Go to your server GTM container → Templates section → next to Tags click "Search Gallery" → find "Meta/Facebook Custom Audiences by Stape" → click "Add to workspace".

4.2 Create a new tag.

Navigate to the Tags section of the server GTM → New → select the tag you just added as tag type.

4.3 Configure the tag.

4.3.1 Action - select the operation you want a tag to perform: add to audience data, remove from audience, or remove from all audiences.

4.3.2 Authentication Type - select the one based on your choice in step 3.

4.3.3 Add Audience ID and Access token.

• Audience ID - go to Audiences section → click on "Columns", check the box next to "Audience ID". When the column appears, copy the ID for the required custom audience.

• Access token - it applies to you if you selected your own credentials as the authorization method. We've explained in detail how to obtain it in the previous step in the collapse element "Own Meta credentials".

4.3.4 Audience members.

The tag can be configured to send data for either a single user or multiple users in one request.

• Single User. Manually enter identifiers for one user using the UI input fields.

Enable Data Processing Options - to support compliance with U.S. state privacy regulations (Limited Data Use), you can enable data processing settings and specify the applicable Country and State.

• Multiple Users. Submit a pre-formatted array of audience members along with a corresponding schema. Each request can include up to 10,000 audience members.

Provide a comma-separated list or array defining the order and type of user identifiers (e.g., EMAIL, PHONE, FN, LN).

Here is an example of tag configuration:

4.3 Add a trigger for the tag.

Specify the condition when you want your tag to fire and send data to the Meta custom audience. In our case, it is a purchase. You can use various triggers, such as purchase event, lead form interaction, or any Facebook event (e.g., add to cart, complete registration) to build custom audiences for targeting/retargeting.

We added the following configurations for a trigger:

• Trigger type: Custom Event
• Event name: purchase
• Trigger fires on: Client Name contains Data Client

5.1 Run Preview mode in both web and server GTM containers.

5.2 Trigger the event you specified in the trigger configuration. In our case, it is a purchase. Find your event on the left-hand menu and click on the Stape's tag you've configured.

5.3 Click on "Outgoing HTTP Requests from Server" - this is the request that is being sent to Meta.

In the request body, you will see "hashed" strings instead of the actual email or name. It is important to clarify that this happens before the data leaves the server to ensure Meta receives it in the required secure format.

The actual data that Meta will receive and process can be viewed in the tag details:

5.4 Check whether Meta actually receives the data.

Go to Audiences → click on the custom audience you send data to → navigate to the tab "History" → there you should see an update.

In case of difficulties with testing the configuration, refer to our guide on debugging and monitoring server-side configuration.

Meta Custom Audiences allow you to target users based on their specific stage in the customer journey. However, the effectiveness of these audiences is entirely dependent on the integrity of your data; if your tracking is blocked by browsers or limited by cookies, your audiences will be incomplete.

By moving the data flow from the client’s browser to a server-side environment, you reduce the impact of tracking restrictions and ensure Meta receives a complete picture of your customer interactions. Stape's solutions eliminate the need to manually manage CSV files and also provide the precise data needed to scale your campaigns.