An ad in a movie can be a static ad having a position in the movie that cannot be moved, or a dynamic ad having a position in the movie that can be changed. When a viewer of the movie wishes to skip a portion of the movie containing the ad, the playback system determines whether the ad is static or dynamic. If the ad is static, then only the portion of the movie preceding the static ad can be skipped, that is, the ad is unskippable; this technique is referred to as “bounceback” since the end of the skip bounces back to the start of the static ad. If the ad is dynamic, then the ad is moved to after the end of the skip; this technique is referred to as “slipad” since the ad slips to later in the movie. When a movie has multiple ads, some can be static and some can be dynamic.