1. A method for converting a plurality of unicast sessions to a multicast session, comprising: receiving a request for establishing a unicast session for delivering content to a first client device; in response to a determination that a threshold number of unicast sessions exist for delivering the content to a threshold number of other client devices, generating a multicast session establishment message adapted for establishing a multicast session with the first client device; and generating at least one multicast session join message for the other client devices, the at least one multicast session join message adapted for enabling the other client devices to join the multicast session.