1. A method of operating a recommender system, which recommender is used for recommending items of interest to users interacting with an online service provider, the method comprising the steps of: (a) setting up one or more policies to be used for influencing recommendations made by the recommender system to a user; (b) responding to a request for a recommendation; (c) causing said recommender system to use at least one of said one or more policies when presenting one or mote policy influenced recommendations to the user in response to said request.