What is a data clean room?
A data clean room is a secure environment where two or more companies, such as a retailer and an advertiser, can combine and analyze their customer data without either side seeing the other's raw records. Queries return only aggregated, privacy-protected results, for example how many people saw an ad and later bought, which enables targeting and measurement without sharing personal data.
Data clean rooms typically match records using hashed emails or other IDs, then enforce rules such as minimum group sizes and blocked row-level exports. Examples include Google Ads Data Hub, Amazon Marketing Cloud, AWS Clean Rooms, Snowflake and LiveRamp's clean room.
They are central to retail media and closed-loop measurement, where a retailer proves ad impact on sales. Clean rooms reduce, but do not eliminate, privacy risk: legal teams still need a lawful basis for the underlying data, and results are only as good as the match rate.