A method is provided for delivering targeted advertisements into a QAM or IP stream that provides accurate synchronization. The method includes synchronizing the internal content of a IP stream delivering video with an advertisement (ad) stream by providing content information in the IP stream and the network stream, the content information including positional information and/or referential information, wherein the positional information is inserted at key locations identified with a PTS value, and wherein the referential information refers to a position in the IP stream or the ad stream, the referential information including either a PTS value or a frame count.