More than 200,000 exclusive books were added to the Kindle store in 2013, and KDP authors sold hundreds of thousands of books during November 2013 through the new Kindle Countdown deals.
Personally, I get a little tired of all the talk one finds everywhere about Konrath and Locke: my feeling is that the true talking-point should be not the small handful of "star players" but all the midlist authors who couldn't make a living through traditional publishing but can through Kindle. This 150+ number tells us that success isn't limited to small number of authors: there'll be far larger numbers in the 50,000 - 100,000 sales bracket, as well.
(And don't forget that many/most of these authors make additional sales from other outlets, too).
And a Happy New Year to all ...