When are they going to add Season [X] from [TV Show] to iTunes?
I would image that the most likely reason for not putting all seasons of a series in iTunes all at once is that ultimately, the networks are trying not to pillage existing DVD sales. If you can pick and choose only a few of your favorite episodes, you’re probably less likely to purchase the entire kit and kaboodle on DVD. By rationing them out season by season, I presume they think that you’re more likely to buy the whole lot of them rather than picking individual episodes. Is that the only reason? Probably not. I’m sure there are technical and licensing issues to consider as well, but not pilfering from DVD sales is probably number one on the list.