Alternative approaches to the insertion of local commercials and messages into networks feeds are provided. Embodiments include digital commercial insertion for cable operators and others that not only offer more flexibility and features, but may also be significantly cheaper to implement. The actual “insert” of the local commercial or message into the digital program is performed by a standard set top box, with several methods of providing the local commercial to the set top box at the proper insertion time. Another embodiment allows a cable operator to significantly save on equipment in the form of splicers and ad inserters, by allowing easy and dynamic mapping of local commercials to insertion zones.