The size of a book is fairly important to me since I tend to prefer large novellas or small novels. Anything that's too long feels drawn out. Anything that is too short leaves me wanting for more. (The only exception are collections of short stories, which I read with an entirely different mindset.) Maybe I'm a bit of an oddball here, but I would actually pay more for a good short novel than I would pay for one of those massive tomes that seem to be popular these days simply because I know that I will finish it.

So yes, size is very important.

Oh, and I'm going to kinda second Quexos' comment on hidden polls. I don't mind hidden polls, but it would be nice if it was only hidden for a week. Attention span issues ... you know, the thing that leads some of us to read shorter books.