1. A method performed by a document server for updating and/or creating a user profile associated with a user of a client device, wherein the document server comprises a recommender system, the method comprising: (i) transmitting, from the document server to the user, a document containing a set of terms, including a first term and a second term, wherein a document profile corresponding to the document associates the first term with a first term value (vd1) and associates the second term with a second term value (vd2): (ii) after step (i), receiving, at the document server, information identifying a set of two or more actions the user of the client device took with respect to the document, wherein the set of user actions is mapped to an action value (iii) in response to receiving the information, determining, for each term included in the set of terms, a value (v) to associate with the term and associating the determined value (v) with the term, thereby establishing a set of term/value pairs, where each said pair consists of one of said terms and its associated value (v), wherein said determining step comprising determining a first value (v1) for said first term of the document, and determining the first value (v1) for the first term of the document comprises obtaining the action value (a) mapped to the set of actions the user took with respect to the document and then calculating the first value (v1) using the obtained action value (a) and the first term value (vd1); and (iv) storing the set of term/value pairs in the user profile.