Synchronization of clients to maximize multicast opportunities

A content monitor includes a processor that at least receives requests from a plurality of clients for content, instructs each client to retry their respective request at a first later time if the request is received before a first time, counts the requests to determine if a number of the requests exceeds a threshold if the request is received before a second time, instructs each client to retry their respective request at a second later time if the counted number of requests does not exceed a first threshold, instructs each client to join a multicast group to receive the content when the number of requests exceeds the first threshold, and counts a number of late clients joining the multicast group after a first portion of the content has been sent to the multicast group.