If you’re a fan of the TV program “Dexter,” you will remember that something rather important happened in the last thirty seconds of the last episode of the last season. If you’ve never watched “Dexter,” imagine an equally important scene in a television program that you do care about. Or game-winning points scored by your favorite team right at the buzzer. Now imagine that you sit down to watch after some delay. In the case of reader K., that viewing is on DVD. That pivotal scene is the first thing you see, part of a promotional clip for… the very DVD you’ve just sat down to watch. So they’re spoiling something you’ve just rented or purchased, assuming that anyone who buys the DVDs had already watched the last season or failed to avoid spoilers?