An online system includes a method for selecting influential users of the online system to be presented with content items. The online system receives input from a third party system specifying the type of users that the content items should be presented to. Based on this input, the online system identifies one or more subject users of the online system as candidates to present the content items to. By comparing the actions of a subject user with the actions of one or more users of the online system determined to be closely correlated with the subject user, the online system determines the expected influence of the subject users. The influence of the subject users is used to determine which users to present the content item to.