A Kindle Single isn’t a new device from Amazon – it’s a short e-book.

And apparently these short e-books are quite popular. According to a new exclusive from PaidContent.org, Amazon has sold over 2 million of them since the new format was launched just over a year ago.

Kindle Singles are longer than short stories, but shorter than full-length novels. They generally range between 5,000 to 30,000 words. They cost less than a full length novel, from $.99 to $4.99. Definitely a more attractive price point for frugal shoppers than paying the equivalent of a hardback book price for a digital book.

The popularity of Kindle Singles has been a benefit to authors who sometimes have medium length stories. Too long for short story, too short for a full novel. Some of the authors interviewed by PaidContent said they had earned tens of thousands of dollars on the sales of Kindle Singles.

There’s only about 165 Singles available on Amazon right now.. Some of the newest are available at Amazon here, and a list of Amazon Singles best sellers is here.