I often wait until a series has finished before committing, because I want to know if it is worth investing my time. That's how I approached The Wire and Breaking Bad, for example. On the other hand, I devoured Battlestar Galactica all the way through, so I'm not always so patient. In the case of the Marvel/Lucasfilm serials, my oldest son insists on regular viewings, so there's no way I can wait and see with those.