Amazon Web Services is preparing to unveil a cloud service to help companies improve the way they target ads to potential customers without violating data privacy laws, according to three people with knowledge of the product. The move comes as advertisers try to recover from, and get ahead of, Apple’s and Google’s restrictions on their ability to track consumers online.

The new AWS service, Bastion, is known in tech industry parlance as a data clean room. It lets multiple companies pool data they have on existing or potential customers without any of them being able to view the entire pool. The idea is to protect the identity of customers, both for privacy reasons and out of competitive concerns. In these metaphorical rooms, companies pooling data—for instance, a retailer like Target and a streaming service that sells ads, such as HBO Max or Hulu—could see how much overlap there is between their respective customers and use that to determine whether Target should target new or repeat customers through ads on the streaming services.