The Sources section allows you to upload external contact lists or use internal segments to enrich your audience and match them with tracked behavior on your website.
There are two main ways to use the Sources section:
Upload a CSV file
Import a list of contacts (emails, phones, user IDs) that you collected outside the platform β e.g., from events, newsletters, other databases.
Use Existing Contacts
Select segments from your already synced or resolved contacts.
Once you upload a CSV or select internal contacts:
The system automatically matches these contacts with existing pixel-tracked users in your database.
If a match is found, the system enriches the anonymous behavior with real identity data.
Matched contacts can then be used in Smart Audiences, Lookalike creation, or exported to Data Syncs (e.g. Google Ads, Meta, etc).
To upload a CSV file, make sure:
It contains at least one identifying column: email, phone, or external user ID.
Columns are clearly labeled.
File is UTF-8 encoded and under the size limit (see upload window for details).
Example CSV format: