Do readers really want a print and a digital version of the same book? Enough to pay a bit more or change their buying habits?

Publishers have been kicking around those questions for years, sometimes dabbling with "bundling" different formats of a title.

With Amazon and UK-based Angry Robot Books both poised to start bundling programs,  the idea will for the first time be tested on a larger scale.

As has been widely reported, Amazon's Kindle MatchBook program will allow buyers of print books (both in the future and dating back to the company's founding in 1995) to get the electronic version for $2.99, $1.99, or $0.99. Amazon said earlier this week that it is just now starting to talk with publishers about participating, so it's unclear how many titles will be available for purchase through MatchBook when it begins in October.

Meanwhile, sci-fi publisher Angry Robot is expanding its Clonefiles program--in which consumers who buy a paperback copy from a participating independent bookstore get the ebook version free. The company says the success of the program in the UK encouraged it to launch US Clonefiles. Angry Robot promises to disclose details soon.

For authors, additional ebook royalties from these programs range from nothing to not much. The question is whether such bundling experiments will ultimately lead to happier readers, and what that will mean for book sales.