Methods and apparatus for hybrid multicast and unicast transmissions in a data network. A method is provided for operating a server on a data network. The method includes computing a multicast cost indicator and a unicast cost indicator that are associated with multicast and unicast transmission of data. The method also includes determining that the multicast cost indicator is less than the unicast cost indicator, and generating a transmission schedule that describes when the data will be multicasted on the data network. The method also includes transmitting the transmission schedule, and multicasting the data according to the transmission schedule.