47. The method of claim 43 , wherein the electronic advertisement is associated with an entity, and the act of delivering the electronic advertisement comprises: positioning the electronic advertisement for display based on a ranking among advertisements for the concept, the ranking being based at least in part on a price parameter offered by the entity.
47. The method of claim 43 , wherein the electronic advertisement is associated with an entity, and the act of delivering the electronic advertisement comprises: positioning the electronic advertisement for display based on a ranking among advertisements for the concept, the ranking being based at least in part on a price parameter offered by the entity. 48. The method of claim 47 , wherein the entity is offered an incentive to provide at least one electronic advertisement.