Systems and methods disclosed herein generate a segment of tracked entities from a collection of profiles merged from different sources. Individuals and other entities use multiple electronic device and online accounts. Options for merging authentication-based profiles and device-based profiles of tracked entities are presented on a user interface accessible to a tracking entity. Systems and methods receive a selection of the options, the selection specifying criteria for merging authentication-based profiles with device-based profiles. Upon generating a collection of profiles by merging the authentication-based and device-based profiles based on the received options, a targeted segment of tracked entities is generated by applying defined segment rules to the collection of profiles.