2. The system of claim 1 , wherein the instructions when executed by the processor further cause the processor to manage how many of the content items are identified as corresponding to each of the plurality of available topics.
1. An electronic magazine system, comprising: a processor; and a non-transitory computer readable medium storing instructions, the instructions when executed by the processor cause the processor to: accept, as input, content items; establish correspondences between individual ones of the content items and individual ones of a plurality of available topics; generate a plurality of profile topics responsive to automatically determined interests of a user; select magazine items from the content items responsive to correspondence between the available topics and the profile topics; assign scores to the profile topics, each of the scores assigned to a corresponding topic of the profile topics, each of the scores assigned based on a number of times that the user has consumed content items corresponding to one of the profile topics over a time period; periodically update the scores by decaying the scores using a pre-defined decay function to produce updated scores; compare the updated scores to determine a stale topic from the profile topics, the stale topic having a lower score than other topics from the profile topics; and remove the stale topic from the profile topics.