I'm back from vacation--a bit brain dead, but anyway. This is a fascinating article in the Wall Street Journal about how companies can monitor your reading on e-books (cue spooky music)....

For centuries, reading has largely been a solitary and private act, an intimate exchange between the reader and the words on the page. But the rise of digital books has prompted a profound shift in the way we read, transforming the activity into something measurable and quasi-public.

The major new players in e-book publishing—Amazon, Apple and Google—can easily track how far readers are getting in books, how long they spend reading them and which search terms they use to find books. Book apps for tablets like the iPad, Kindle Fire and Nook record how many times readers open the app and how much time they spend reading. Retailers and some publishers are beginning to sift through the data, gaining unprecedented insight into how people engage with books....

Mr. [Jim] Hilt[, Barnes & Noble's VP of e-books,] says that the company is still in "the earliest stages of deep analytics" and is sifting through "more data than we can use." But the data—which focuses on groups of readers, not individuals—has already yielded some useful insights into how people read particular genres. Some of the findings confirm what retailers already know by glancing at the best-seller lists. For example, Nook users who buy the first book in a popular series like "Fifty Shades of Grey" or "Divergent," a young-adult series by Veronica Roth, tend to tear through all the books in the series, almost as if they were reading a single novel.

Barnes & Noble has determined, through analyzing Nook data, that nonfiction books tend to be read in fits and starts, while novels are generally read straight through, and that nonfiction books, particularly long ones, tend to get dropped earlier. Science-fiction, romance and crime-fiction fans often read more books more quickly than readers of literary fiction do, and finish most of the books they start. Readers of literary fiction quit books more often and tend skip around between books.

Those insights are already shaping the types of books that Barnes & Noble sells on its Nook. Mr. Hilt says that when the data showed that Nook readers routinely quit long works of nonfiction, the company began looking for ways to engage readers in nonfiction and long-form journalism. They decided to launch "Nook Snaps," short works on topics ranging from weight loss and religion to the Occupy Wall Street movement....

Amazon, in particular, has an advantage in this field—it's both a retailer and a publisher, which puts the company in a unique position to use the data it gathers on its customers' reading habits. It's no secret that Amazon and other digital book retailers track and store consumer information detailing what books are purchased and read. Kindle users sign an agreement granting the company permission to store information from the device—including the last page you've read, plus your bookmarks, highlights, notes and annotations—in its data servers.

Amazon can identify which passages of digital books are popular with readers, and shares some of this data publicly on its website through features such as its "most highlighted passages" list. Readers digitally "highlight" selections using a button on the Kindle; they can also opt to see the lines commonly highlighted by other readers as they read a book. Amazon aggregates these selections to see what gets underlined the most. Topping the list is the line ["Because sometimes things happen to people and they're not equipped to deal with them"] from the "Hunger Games" trilogy. It is followed by the opening sentence of "Pride and Prejudice."