1. A method for determining a user attention to at least one multimedia data element (MMDE) displayed in a web-page over a user computing device, comprising: receiving a request to determine the user attention, wherein the request includes at least the web-page and an identification of the at least one MMDE in the web-page; receiving at least one sensory signal captured by at least one sensor connected to the user computing device; querying a deep-content-classification (DCC) system to find a match between at least one concept structure and the received sensory signal, wherein the at least one concept structure includes a plurality of metadata associated with reduced clusters of MMDEs, the clusters represented by a compressed number of signatures; receiving a first set of metadata related to the at least one matched concept structure; analyzing the returned set of metadata to determine the user attention with respect to the at least one MMDE; and associating the at least one MMDE with the determined user attention.