Abstract: This document describes techniques for expanding user groups while preserving user privacy and data security. In one aspect, a method includes receiving, by a content platform and from a client device of a user, a request for a digital component that also includes a user identifier. A determination is made that the user identifier is included in a user list that includes multiple user identifiers respectively corresponding to multiple users in a user action group. In response to determining that the unique identifier is included in the user list, a digital component of the entity for which the user list is generated is selected and provided to the client device of the user for display to the user of the client device.

Abstract: A method is disclosed for providing, for display to a content provider, a user interface comprising an option to view new audiences to be added to a plurality of users currently designated to receive content of the content provider, receiving a user selection of the option, and causing display of information identifying the new audiences, the information identifying the new audiences comprises, for each new audience, an audience identifier, an indication of an estimated number of user actions related to the content of the content provider, and an option to request that a corresponding audience be added to the plurality of users currently designated to receive the content of the content provider.

Abstract: Methods, systems, and media for providing audience recommendations are provided.