Audiences and data

First-party data

Updated 25 Oct 2026

First-party data is information a business collects directly from its own customers and visitors, such as bookings, inquiries and email sign-ups. Ad platforms let advertisers upload it to reach those customers again or find similar people. Google's Customer Match is one example. Since early March 2024, Customer Match lists no longer run on Google's partner sites or third-party exchanges in the EEA, the UK and Switzerland. They still run on Google's own properties.

Privacy law applies in both markets:

UK: the ICO (2 Apr 2026) says you must have a valid lawful basis to handle personal information.
US: California's CCPA (page updated 28 Aug 2026) gives people the right to opt out of the sale or sharing of their data.

Example: a tour operator uploads past guests' emails to leave them out of a first-trip offer.