An exemplary method includes a digital advertisement insertion optimization system accessing data that indicates a playback return position at which playback of a media program is to be resumed following insertion of an advertisement in the media program when a first media file comprising the media program encoded in a first media format is used for playback of the media program, analyzing a second media file comprising the media program encoded in a second media format to identify a set of key frames within the second media file, selecting a key frame from the identified set of key frames; and generating data that indicates a new playback return position at which playback of the media program is to be resumed following insertion of an advertisement when the second media file is used for playback of the media program.