I dunno. it depends on the subject I guess. I don't think it hurts the artform so much as it makes books less appealing. If I'm in a hurry, I don't want an investment in a 1000 page tome. I don't want to keep up with a 12 book series. Especially if it's gonna be $20 just to try it out.

I'd personally rather see a series of one-off short books for $2.50. That would be low enough to be atractive to young kids and adults with very little free time. Yeah, they should be long enough to cover the subject, but the idea that more pages = better is bunk. It's another barrier to reading -- the books cost more, they try to get you to buy a whole series (if you just read HP:DH, you'd be lost for the most part).

I'm kinda turned off by trilogies and series in general (LOTR and Dune excepted). The whole idea of that and the similar style of TV shows is to force you to buy or watch multiple stories in the same series -- otherwise you'll be lost. What better way to sell LOST or 24 DVDs than to make sure that anyone who hasn't seen every episode is completely lost? Same with book series -- they'd be better trimmed down to a single story, but then you couldn't force your audience to buy multiple books. It's a cheap trick.