Some shows are good enough that you want to watch the episode when they come out. Watching it online still separates you from the schedule though. If the show airs at 8pm, you don't have to watch it at 8pm, you can watch it when you have time. But there's a difference between a couple of hours/days and a couple of months (maybe waiting for a dvd release to buy it, or for a local station to rebroadcast for your country).