Page numbers. When you hold a dusty old paperback, that relic of a previous age, you feel its weight, you fold its pages (I do at least), and you have a very good idea of how close to the end of it you are. You can't help but realize that the story is about to end. The bittersweet sense of ending that comes with those final few chapters always heightens the denouement. Bibliophiles of all sorts manage their expectations and readjust their predictions when entering the homestretch. This hard learned skill, which comes with years of reading, doesn't work with the Kindle.
Case in point, I was reading Leviathan Wakes (★★★★☆) at 48% completion on the Kindle when the book ended. That made me mad. To be fair it felt like an ending but I didn't know it was the ending. I wasn't ready for it. I was expecting another 52% of adventure and intrigue. Instead I got a second book I had absolutely no interest in. This made me even more mad.
I don't mind moving from paper to digital. For me it makes a lot of sense. Lower costs and fewer bookshelves are big advantages of the digital revolution. Well, perhaps not costs. If you read spec fic most of the hot items are at a premium, but that is a conversation for another day. After I go buy a pitchfork or two.
Back to premature endings. I hate them. I hate endings to start with, but with the knowledge that they are coming, I can get myself ready. In the words of a somewhat popular television show, I can "brace for impact". Not so with the Kindle. With the Kindle the ending is thrust upon me without warning or explanation because some industrious publisher thinks that giving me a free book (the first book in a 5 part series I might add) makes good business sense. And maybe it does. But it also destroys the illusion that what I am reading is an old-fashioned book. And I like my illusions.
Hear me o Kindle gods and place dividers in your books so that your endings are no longer premature. No one likes premature endings.