1. A computer-implemented method comprising: accessing user preference profile information identifying one or more preferences of a user; accessing user history information identifying one or more content items previously accessed by the user; determining that a particular content item includes features matching the preferences identified in the user preference profile information; determining that the particular content item is dissimilar to the content items identified in the user history information: determining that the particular content item is relevant to the user based on the determination that the particular content item includes features matching the preferences identified in the user preference profile information and the determination that the particular content item is dissimilar to the content items identified in the user history information; and providing the particular content item to the user, based on the determination that the particular content item is relevant to the user.