If you watch enough Twitch channels, you may have seen a Premiere -- a pre-recorded video that debuts as a live stream. It lets broadcasters recreate the thrill you'd expect from a TV show premiere, just in an online format. Sound like a good idea? Facebook agrees. It's testing Premieres, an option that lets creators launch canned videos as Facebook Live moments, complete with real-time chats. You can check out a movie trailer or Watch show at the same time as everyone else, rather than racing to watch them on your own before your friends spoil everything.