well i’m sure i certainly don’t know.
all i know is that personally, i prefer them. i like the non-linearity of a book. read it, then refer as you please.
my first real 3d app was lightwave 5.0 and i didn’t have a computer at the time so i just took the books home, read them cover to cover and when it was time to gear up for the project… i was pretty much ready!
so yah, i can’t be sure what sales figures are like compared to dvds.
all i can say is that if YOU made a book, i would certainly put it on my amazon pre-order list.
which… is… really… full… of delayed… zbrush books…
sigh.

jin
p.s. i know i’m different from most of the artist community in this way but i have never and will not buy an instructional dvd. for me it’s not a good value at all. i want lots of info and don’t need that much depth of techniqe. dvd’s are the exact inverse. i can figure out the depth of technique. i just want to be filled in on the big salient points that i could be missing and you can squeeze a lot more of that into a book than a video.
video is real time… uncompressed…  i want to learn on fast forward.
 i want to learn on fast forward.
but then again, a book is probably much more work.