1. A method, comprising: organizing advertisements according to their meaning into a lexicon, the lexicon defining elements of a semantic space represented by a network of interconnected meanings; receiving a concept; determining one or more concepts close in meaning to the received concept; identifying one or more advertisements in the semantic space related to the received concept and the one or more concepts close in meaning to the received concept based on meanings of the advertisements; and transmitting for display the one or more advertisements based on an order, the order corresponding to a relationship between monetary values determined for each of the one or more advertisements identified as related to the received concept and the one or more concepts close in meaning to the received concept.