Amazon's famously protective of its Kindle ebook sales numbers, but paidContent reports today that it was given permission to take a look at how sales of the company's short-form Kindle Singles have been going. Apparently, Amazon's pushed over 2 million copies of the titles, which range from 5,000 to 30,000 words each. That number doesn't mean much on its own, but it's impressive when you take into account that only 167 Singles are currently available and that the program got its start less than 14 months ago in late January of last year. Amazon markets the titles as "compelling ideas expressed at their natural length," the concept being that authors needn't crimp their work to fit it into a magazine nor fluff it out for it to exist as a standalone book. Amazon gets 30 percent of each sale, and, according to paidContent's estimates, that comes to a total of $1.12 million in revenue since the program's launch.