How does purchased video differ from other video?
Videos purchased from the iTunes Store have FairPlay digital rights management embedded in the files and are in a format that can be readily synced to a video capable iPod. Just like with music you purchase from the iTunes Store, you own the videos you purchase. You can authorize up to five computers to play purchased videos, and you can sync the video to as many iPods as you like. An iPod can contain purchased content from up to five accounts; iTunes will not allow you to add data from a sixth account to iPod.
