The problem with these surveys trying to prove the superiority of pbooks (aside from bring meaningless) is that all they manage to achieve is to document the steadily growing acceptance and preference for ebooks.
29% is a nice number. Certainly better than last year's 19%.
The traditionalists really need to phrase their surveys better to get the results they want.
Like: "If I point a gun to your head, will you say you prefer print over ebooks?"