19. The system of claim 15 , wherein the system is further configured to receive content items from a stream of content of other users with whom the first candidate user has a relationship and generate additional content items for the stream of content of the first candidate user based on the received content items.
19. The system of claim 15 , wherein the system is further configured to receive content items from a stream of content of other users with whom the first candidate user has a relationship and generate additional content items for the stream of content of the first candidate user based on the received content items. 20. The system of claim 19 , wherein generating the additional content items comprises weighting the additional content items based on user interactions between the first candidate user and the other users.