In addition to the fact that $15 million was added to NBC's purse, you have to think of the long term effect of iTunes. Look at The Office which was greatly helped by the fact that people discovered it on iTunes. Last season alone they did three "producer's cuts" for iTunes because so many people were purchasing them through that service. So iTunes not only created the revenue for the show, but helped it become a hit which created greater ad revenue. There have been quite a few shows that I've discovered because of a free episode or because I saw it on the main page of iTunes. I dare say that iTunes is an important part of the strategy to bring NBC into first place in the ratings.
If you want to say that $15 million is a paltry sum for a revenue stream, I would agree that a corporation like NBC would like to see that grow, but give it time. I had four season passes last season and all of them were from NBC Universal. That's over $100 of my money that they won't get from me this season.
They'd argue that it was because iTunes had a ready delivery mechanism, which they now have many alternatives to, including ones they've had a direct hand in crafting. So, if consumers flock to Hulu and continue to use NBC.com as they'd like (despite the, at times, HARSH difference between how NBC does video and how ABC does it) they'll be more than pleased to move on without iTunes. I was watching videos on NBC.com the other day, and they freely bounced from Quicktime movies to Flash, with varying volume controls in their ads. It was a complete mess. They're just throwing crap at the wall right now. It seems clear their departure from iTunes isn't going to hurt anything more than their image. --And I think it has done serious damage... considering the harshness of the remarks. This is a war apparently. --Worse, other executives are certainly listening.