It would be interesting to see a breakdown in reading habits of the general public. I think that would help to see how to best market e-books. As things stand, the type of reader who is a collector, who likes to put their books on a shelf and look at them and take them down and pet them occasionally (oh, and re-read them, too, of course) will not be an e-book consumer. They like the object as much as the story.
The type of consumer who buys whatever is around in the airport or wherever they happen to have some downtime and think about reading, who then give the book away to someone else to make room in their carryon (I witnessed such an event on an airplane last week), will not be an e-book consumer. They would have to purchase an expensive reader and have it with them at all times. Bringing down the price of the reader might help, but it needs to be portable. If they can be wheedled into reading on their PDA or smartphone that they already have with them, and buy e-books easily at the airport or drugstore, or better yet download it over the air, then maybe.
The consumers I can see purchasing e-books in large numbers are those who read a lot of books, buy in quantity, and don't care to keep the books after they have read them. These are the people who always have a large TBR pile, who keep lots of books in queue. I can see them buying lots of books and loading them to their reader, keeping their reader with them, and reading down their list, then buying another pile. For those people, the reader can cost a little more (probably) but the books need to be CHEAP CHEAP CHEAP. Otherwise, they'll just do what they've been doing all along and taking a box of last month's books to the Gently Used Book Emporium and trading them for next month's reading material. This already is happening in a small way in the romance category.
Then there are the geeks, who like the gadgets and don't mind paying for them.
But again, the prices of the books needs to come down to keep people buying.
Library readers are also a good market, but the readers need to be CHEAP CHEAP CHEAP because they are too cheap or broke to buy books; or like me, live in tiny flats with no place to store umpteen books.
Speaking of--that's a big market right there. I figure I could clean off three or four bookshelves just replacing my copies of classic novels with free e-texts. Once I get an eink reader (either the Bookeen or the Kindle--waiting till they both come out to decide), I will do so; have already started in a limited way with downloading some books to my Treo and ditching the pbooks. I could even weed out a few more shelves of, say, my Stephen King and John Grisham hardbacks. More room for weird and obscure history reference books, yay! Or maybe even a plant or something.
But lots of the books I would happily replace with e-books aren't available. For instance, I love L.M. Montgomery's Anne of Green Gables series--but all of the books aren't available, because some of them are on the wrong side of the public domain cutoff and no one has bothered to publish them. I'd PAY for them, but they're just not available. The public domain stuff is out there, both free and for small fees. Laura Ingalls Wilder is another one--my copies of her books are falling apart anyway, but they're not available as e-books. Patrick O'Brian, same thing. Georgette Heyer, same thing. In some cases I prefer the physical books, but with those writers, I have beat-up, acidic-paper-printed-turning-brown paperback copies anyway, so I would actually rather have them as e-books. I just want the story; the physical medium is unimportant to me.
I think I'm preaching to the choir here, but they simply haven't hit the sweet spot between price and availability on readers and books yet. I think we're back to getting the publishers on board...