Scott Berkun discusses what he sees as the highest impact innovation in terms of books prior to the Kindle:
The invention of cheap paperback books, Penguin makes books cheap enough for the average citizen (1935). This was a revolution in the U.S. as it made books cheap, portable and part of middle and lower class culture.
If anything I think paperback books are the best comparison as they were a revolution in distribution, access, convenience and portability much like the Kindle is. They also revolutionized the business model for authors, publishers and bookstores, much like Kindle will if it’s success continues.
I think he has a solid point here. Movable type was critical for making it possible to mass produce and widely distribute the written word. Paperbacks had a similar impact, by reducing the price and the physical characteristics of books, further widened their distribution. The Kindle has similarly impacted the ease with which books can be distributed, both in terms of geography and speed.
But I wonder if there isn’t another innovation, or significant change, that impacted the book more than either movable type or the paperback. My instincts tell me that the advances in literacy and its growth outside of elites would have had a major impact on the adoption and distribution of books. Was this due to compulsory education? Advances in economics, trade, etc.? Now of course there is a chicken-and-egg scenario here: did the increase in literacy rates make books more desirable or did the mass distribution and increased affordability of books contribute to increased literacy rates? I am sure someone has teased this relationship out, I’m just not aware of the literature.