Sync Customer Segments with Google Ads and Facebook Ads

Once an audience is connected, CaptainBook keeps it synchronized automatically as customers enter or leave the segment.
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💡 Available on Extended and Ultra plans
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Ad Audience Sync requires Customer Segments and is not available on Free, Starter or Legacy plans.
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You will need:

You will also be asked to accept the Data Processing Agreement before CaptainBook sends any customer data to an advertising platform.

Go to Customers → Segments and open the segment you want to use.

Then select the Ad Audiences tab.

This page shows any audiences already connected to the segment, their current status, and the option to create a new one.
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Click Create Ad Audience and choose the advertising network you want to use:

If the account has not been connected yet, CaptainBook will ask you to sign in and authorize access.

You only need to connect each advertising platform once. Once connected, the account can be used with other customer segments as well.
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⚠️ Using an advertising agency?

You need sufficient permissions on the advertising account to complete the connection. If your agency manages the account, they may need to grant you access or complete the authorization with you.
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Enter an Audience name and, optionally, a description.

Then choose the Audience type:

Select the Facebook Ads account you want to use.

Once configured, click Create Audience.

Select the Google Ads account you want to use.

Then choose whether CaptainBook should:

If you create a new list, enter the name you want to use in Google Ads.

Once configured, click Create Audience.

💡 Naming tip

Name audiences after the customer rule rather than a specific campaign.

For example, use Repeat customers — 2+ bookings instead of Summer 2026 campaign. This makes the audience easier to reuse later.

CaptainBook creates or connects to the audience on the selected platform and starts syncing the customers currently included in the segment.

During the initial upload, the audience may show as Backfilling. Once the initial sync is complete, it becomes Active.

From then on, CaptainBook keeps the audience updated automatically.

When a customer starts matching the segment, they are added to the advertising audience.

When they stop matching the segment, they are removed.

You do not need to manually export customer lists or upload CSV files again.

Backfilling
The initial audience upload is still in progress.

Active
The audience is syncing normally.

Sync paused
CaptainBook needs an action from you, such as reconnecting the advertising account.

Sync error
The advertising platform rejected part of the sync. Check the displayed error message.

If an audience has been deleted directly from the advertising platform, the sync pauses. Use Sync now to recreate and refill it.

CaptainBook pushes updates at different frequencies depending on the platform:

For segments based on bookings or customer information, customers are removed when they stop matching the segment.

For segments based on browsing behavior, removal has a 48-hour delay to prevent customers from repeatedly entering and leaving an audience because of short-term browsing changes.

CaptainBook uses customers':

These values are hashed using SHA-256 before leaving CaptainBook, following the matching requirements of the advertising platforms.

CaptainBook does not send information such as:

The advertising platform receives only the information required to match customers with its own users.
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⚠️ Hashing does not make the data anonymous

Hashed contact information is still personal data. You remain responsible for having the appropriate lawful basis to use your customers' data for advertising audience matching.

Not every customer sent to an advertising platform will be matched.

For example, a customer may have booked using a different email address from the one associated with their Google or Facebook account.

Because of this, the matched audience shown by the advertising platform may be smaller than your CaptainBook segment.

CaptainBook displays a warning when a synced audience contains fewer than approximately 100 customers.

If your audience is very small, consider starting with a broader segment and narrowing it later.
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💡 Advertising platforms can change their audience-size requirements. Check Google Ads or Meta Ads Manager for their current minimums before planning around a specific number.

Create a segment of previous customers and advertise to people who already know your business.

For example:

Customers who booked more than 6 months ago
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Create a segment containing high-value customers, such as people who have booked multiple times, and use it as a source audience for prospecting tools available on the advertising platform.

Sync your existing customers and exclude that audience from acquisition campaigns.

This prevents you from spending acquisition budget advertising to people who have already booked with you.

You can also create more specific exclusions, such as:

Customers who booked within the last 30 days

This can prevent customers from continuing to see ads for an experience they have already purchased.

When you use Ad Audience Sync, you remain the data controller.

This means you are responsible for making sure you have the right to share customer contact information with advertising platforms for audience matching.

Depending on your jurisdiction, this may include:

If a customer should no longer be used for advertising, the easiest approach is to exclude them through the conditions of your CaptainBook segment. Once they stop qualifying for the segment, CaptainBook will remove them from the synced audience automatically.
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If you're unsure whether your current privacy policy or consent process covers this use, check with your data protection adviser before enabling the feature.