The invention provides a method for updating a user profile on a server (2) based on user content items on a client (1), the server (2) being able to communicate with the client (1) via a communication network (3), comprising the following steps: a) for each of at least a part of said user content items on the client (1), providing characteristic information suitable to identify a respective user content item; b) transferring the characteristic information of the user content items from the client (1) to the server (2); c) comparing the characteristic information of the user content items with characteristic information suitable to identify the server content items; and d) updating the user profile on the server (2) based on the comparison carried out in c).