1. A method for building a user interest profile, comprising: identifying features of each of a plurality of articles; for a given user, logging views of one or more of the plurality of articles, the one or more of the plurality of articles being provided by a content server over a network to a client device for viewing on the client device; for each view, measuring a corresponding dwell time for the view by the given user, wherein measuring the corresponding dwell time includes processing interaction data received over the network from the client device; for each view, applying a corresponding weight based on the corresponding measured dwell time, wherein applying the corresponding weight to each view uses a logarithm of the corresponding measured dwell time, such that a weighted view is separately determined for each single view of one of the articles; determining user interest scores for features of the one or more of the plurality of articles based on the weighted views; generating a user interest profile for the given user based on the user interest scores; wherein the method is executed by at least one processor.