1. A method for inferring user interests based on metadata of a plurality of multimedia objects captured by a plurality of users, the method comprising: receiving, for each of the users, metadata describing each multimedia object in the plurality of objects associated with that user, wherein each multimedia object includes one or more attributes imputed to that object based on the metadata; identifying one or more concepts from the one or more attributes, wherein each concept includes at least a first attribute that co-occurs with a second attribute imputed to a first multimedia object; and associating a first one of the plurality of users with at least one of the concepts based on the attributes imputed to multimedia objects associated with the first one of the plurality of users.