Systems and methods of implementing a finite-state machine using electronic notifications delivered to a client device in a computer networking environment are provided. A content item can be received, along with first and second notifications associated with the content item. The first and second notifications can be stored in a queue. In some implementations, a state machine can be maintained in which at least some states may cause the first or second notifications to be displayed, and in which transitional conditions between states may depend at least in part on user interaction with the displayed notifications.