From the New York Times article by DAVID STREITFELD:
"Before the Internet, books were written — and published — blindly, hopefully. Sometimes they sold, usually they did not, but no one had a clue what readers did when they opened them up. Did they skip or skim? Slow down or speed up when the end was in sight? Linger over the sex scenes?
A wave of start-ups is using technology to answer these questions — and help writers give readers more of what they want. The companies get reading data from subscribers who, for a flat monthly fee, buy access to an array of titles, which they can read on a variety of devices.
. . . Some general insights: The longer a mystery novel is, the more likely readers are to jump to the end to see who done it. People are more likely to finish biographies than business titles, but a chapter of a yoga book is all they need. They speed through romances faster than religious titles, and erotica fastest of all. . . readers are 25 percent more likely to finish books that are broken up into shorter chapters. That is an inevitable consequence of people reading in short sessions during the day on an iPhone."