1. For use in a content delivery network having a plurality of users associated therewith, a method of delivering targeted advertising or promotional content to a selected one or more of said users, said method comprising: identifying said one or more users from said plurality using descriptive information relating to said one or more users, said descriptive information being selected so as to correlate to at least one of a demographic or psychographic; identifying one or more advertising or promotional content elements based at least in part on said descriptive information, said act of identifying one or more advertising or promotional content elements comprising: accessing first metadata in a primary content stream, said primary content stream having said one or more advertising or promotional content elements placed therein and said first metadata comprising at least timing reference information of descriptive codes associated with said primary content stream; accessing second metadata configured to describe at least one of said advertising or promotional content elements; and evaluating a correlation of said first metadata with said second metadata to determine which of said one or more advertising or promotional content elements are most contextually relevant within said primary content stream at a particular point in time; selectively delivering said one or more advertising or promotional content elements to said one or more users via said network based at least in part on said correlation of said first metadata with said second metadata; and receiving information indicating that at least one of said one or more users has tuned away from said advertising or promotional content elements, said information being used to identify one or more second advertising or promotional content elements for subsequent delivery to said one or more users.