One of the most innovative e-book apps available today, Inkling, has just updated its iPad app, adding new features to make its already-interactive textbooks even more interactive and more social. As I've argued recently, that social element is crucial, particularly in education, as it means that readers no longer need be isolated with just them and their textbooks. Indeed, inside each Inkling textbook now is a study group in which anyone reading the book can participate.

The Race to Digitize Textbooks

Even though digital textbooks are a relatively new phenomenon, there is already a sizable number of competitors in the space: Barnes & Noble's Nook Study, CourseSmart, and Kno, for example. The textbook rental company Chegg announced last week that it was getting into the e-book business, and Amazon recently said it was getting into the textbook rental business. All this makes it incredibly difficult to compete when you're a small ed-tech startup, particularly when, as is the case with Inkling, your catalog only offers a small selection of textbooks.

It's been a year since Inkling launched its iPad app, and in all fairness, its catalog has grown substantially over the past 12 months. Inkling now offers 50 textbooks and says it will have 100 by year-end. "What's taking it so long?" you might ask, looking at the 100,000 titles that its competitor Kno now boasts.

Inkling is different from other e-book apps as it doesn't simply digitize the printed textbook. Rather it "gently dissassembles the textbook," says Matt MacInnis, Inkling founder and CEO -- re-engineering, if you will, rather than simply re-purposing in an electronic format. Content in Inkling isn't bound by pages or sections or chapters in the same linear fashion as a printed book. Rather, it's organized via a knowledge hierarchy, of sorts, all richly illustrated and augmented. An Inkling textbook is interactive. And it's social.

When a Digital Textbook Becomes a Study Group

With Inkling 2.0, launching in the App Store today, that social element has just been greatly augmented. When you download a title now, you'll join what MacInnis says he hopes will become the "world's largest study group" -- a social network, of sorts, connecting all the students and professors who are using that book in class. To this network, you can share your highlights and your notes. You can pose questions, and ideally of course, you can find answers. Even better, you can find them in real-time.

But even as someone who's awfully fond of marginalia, I had to ask MacInnis if this wouldn't make the margins of a textbook noisy to the point of uselessness -- much like those used textbooks you see that have had several previous owners, all of whom have used different color highlighters to mark up what they thought significant. Thousands upon thousands of students use the Marketing Management textbook, for example, and it could be a little unwieldly to try to read and study if your textbook has become a chatroom. To that point, MacInnis says that Inkling will use your existing social graph -- linking to your Facebook profile -- in order to surface the comments and notes from those you know. They'll be dynamically sorted and ranked based on likes. And while people will be able to interact in real-time, you'll have the option to turn this feature on and off and see only the responses from the people you know or trust.

Is Inkling's Innovation Enough?

Despite the innovation at work here (and despite a recent $17 million investment round), critics of Inkling will no doubt point to its catalog with skepticism about whether or not the startup can pull this off. For his part, MacInnis does insist that the books the startup offers are the "market leading titles," and the company is emphasizing re-engineering those rather than boasting some large, inflated number that doesn't really represent what students actually are assigned in college.

Inkling also allows students to purchase chapters, rather than the entire book, and the company makes one chapter of each title available for free for purchase by the chapter. Because while, sure, features matter and selection matters, at the end of the day for most college students, it's the price that's the most important factor.

So even with this smart new Version 2.0 of its e-book app, Inkling does have its work cut out for it, particularly as other e-book apps start to include more bells and whistles of their own and as printed textbooks -- particularly used printed textbooks -- still win on price.