By Hannah Johnson

Yesterday, Amazon began selling its Kindle Singles online. Singles are e-books between 5,000 and 30,000 words long. According to the press release, these e-books are meant to “allow a single killer idea — well researched, well argued and well illustrated — to be expressed at its natural length.”

Singles are priced between $0.99 and $4.99 (though at this time, none of the titles are priced above $2.99). Singles available include fiction from Jonathan Littell and Jodi Picoult, as well as nonfiction, diet, journalism and business titles. In fact, the number of titles available though Kindle Singles appears to be increasing hourly (in writing this post, I’ve checked the list several times, and it’s grown each time). Publishers and writers seem to be eager to try out this new format.

The Kindle Singles concepts was announced back in October 2010.

Coinciding with the availability of Kindle Singles is the launch of TEDBooks, a series of e-books from TED Conference speakers. Each TEDBook is 20,000 words or less, a length that will “allow someone to see an idea fleshed out in a satisfying way — but without having to devote a week of reading time to it.” According to the TEDBooks website, “The mass adoption of new e-book technologies like Kindle and iPad has changed the rules of the game. We suspect the traditional length of books has been dictated as much by the constraints of the physical medium of print as by what a modern reader actually wants.”

The New York Times spoke to Chris Anderson, curator of the TED Conference, who said that “Amazon takes a 30 percent cut of revenue and the rest is split evenly between TED and the author.”

The concept of selling e-books that are not long enough to be a book but too long to be published in a magazine seems to be in vogue. Publishers have been selling short stories in e-book format for some time now, and we reported earlier this month about a project called The Atavist, which aims to publish longform journalism in the 12,000-word range.