So watching a favorite TV rerun while you're procrastinating may not be actual procrastination -- it may be a way to get your brain recharged to go after your task with renewed energy.
A researcher at the University of New York at Buffalo found that our brains like the "break," so to speak, of watching something we're already familiar with. That could explain why we get a little bit more enjoyment from an appreciated rerun than you'd think it would merit when everything we're seeing is already known to us.
I'm not sure of all of the neurological ins and outs of the research, but I know that there are some reruns I'll watch again and again. WKRP's turkey episode is one. The Frasier episode in which the entire cast pursues a romantic liaison with one another while at a weekend cabin will get me every time. And the post title is taken from a Cheers episode in which Sam is challenged to a phone-number collecting contest by the obnoxious Henri, when Henri gets the first hint that he may not have the inside track that he thought he did. I've seen it a dozen times and I crack up every time.
It also has a valuable moral to teach. Sometimes, even when you win, you lose.