Maybe, as many have already said, the ebook sales of the Big 5 are down and all others are up. I for one own >300 ebooks that are not from the Big 5, and then I haven't even factored in my thousands of public domain books. (I once had a chance to dump the entire public domain part of the Feedbooks server because their file naming was VERY predictable at that time...
)
I have bought some very large and heavy illustrated Tolkien works, but to be honest, I don't like to read them anymore. After reading on a Kindle for about 4 years now, reading a book that weighs over 2,5 pounds and is 4 inches thick is really hard. I never thought I would say that, but it's true. I'm not even talking about talking such a book on public transport. It's a pity e-readers can't yet compete when pictures and illustrations are involved; for any other 'normal' novel though, I won't touch paper again if I can help it.
So over here, ebook buying won't go down. (But I do have more books than I need, for at least the next 10-15 years...)