The information is coming from companies that provide vast electronic libraries to users of e-readers, the New York Times reported Tuesday.
Scribd, a digital library, last week made a deal with Smashwords to add 225,000 books to its subscription service. Scribd is just beginning to collect data, but this is what it had found so far: readers become more likely to jump to the end of a mystery novel the longer it is; only one chapter of a yoga book is read; romances are read faster than religious books; erotica is read faster of all.
A similar service, Oyster, has found readers are 25 percent more likely to finish books with shorter chapters.
Officials of the companies are upbeat about what all this data can mean for the future of books, the Times said.
"Self-published writers are going to eat this up," said Mark Coker, the chief executive of Smashwords.
Scribd's chief executive, Trip Adler, said, "We're going to be pretty open about sharing this data so people can use it to publish better books."
Quinn Loftis, a writer of young adult paranormal romance, said such data complements her already extensive connections with her readers through her website and numerous social media sites.
"What writer would pass up the opportunity to peer into the reader's mind," she asked.