COMMERCIALS ON MOBILE DEVICES

Among other things, a video item is downloaded to a mobile device from a digital video recorder. The video item includes a video program and commercials that have been previously embedded within the video item. Before, during, or after the download of the video item, information is reported from the mobile device to a server about the video item, from which the server can select a set of substitute commercials. One or more of these substitute commercials are downloaded from the server. When the video item is presented on the mobile device, the mobile device replaces at least one of the original commercials that has been previously embedded within the video item by a substitute commercial that has been downloaded to the mobile device.