The first genre book I ever read was Terry Brook’s The Sword of Shannara. I was eleven years old, it came from my dad’s book collection and it was so thick you could probably club baby seals with it. When my friends saw me tackling this monster, they told me I would never get through it all, but I did and I was quite proud of the accomplishment.
I don’t know how much the length of books influences whether or not readers take them up, but I suspect it plays a part, though most readers probably aren’t attempting to lift their social status by reading thick books the way eleven year old me did. I’ve read in several places that publishers believe people who read certain genres (fantasy for one) buy books based on weight (among other things) and that’s the reason we have so many epic door stopper fantasies (or is that epic fantasy door stoppers?).
Before I switched to audiobooks and ebooks (some time in 2004) I perceived thicker books as being better value for money, after the switch I slowly changed my mind. If an audiobook is listed as 40 hours long, I’ll thick twice about whether or not I really want to spend that much time with it, but I won’t give a second thought to buying a book that sounds mildly interesting and comes in at a reasonable 10 hours even though both books cost exactly the same.
If you’ve ever challenged yourself to read a book a week for an entire year (I managed to do it in 2009 and 2010) you come to appreciate shorter books when you drop behind your target. As more people move to ebooks (and we see less paper books) and they share their reading habits on Goodreads, Library Thing, and Shelfari, it’s not going to be the length of the books that impresses people, but the number of books they churn through. There is still something to be said for being widely read, and as ebooks remove the restrictions the production process places on book length there is no reason for authors to avoid shorter work.
When you stop to compare your memory of the shorter books you’ve read with the longer books you’ve read, I’ll be surprised if the shorter books don’t take up as much memory (or almost as much) as the longer books. It’s the ideas the books present that stay with me, not the word count, and books twice as long don’t always present twice as many ideas.
Reading shorter books exposes readers to more ideas, and writing shorter books allows writers to play with more ideas and try new things.
Charlie Stross has a post that talks about why books are the length they are, and in it he states that he and his publishers can make (probably) twice as much from two 300 page books as they can from one 700 page book. From an economic position, that suggests writers could make more from four 150 page books than they could from two 350 page books. As ebooks inevitably bring down the price of books, and people start accepting shorter books as normal and realize they fit better into their busy schedules, many writers will start thinking about novella length books.