iDreamBooks, book review aggregator, deems itself the "rottentomatoes.com for books." iDreamBooks searches reviews across media outlets and compiles the data to a single, comprehensive repository of review. iDreamBooks offers developers access to the reviews through the iDreamBooks API.
Before 1500, monks spent their lives copying the Bible by hand. That method was replaced by printing presses for the next 500 years. Today, ebooks are set to end the practice of pulping trees and smearing them with ink. In all this change the direction of information access has been constant for half a millennium: faster and faster, easier and easier. The next revolution for publishers is APIs for books.