As ebooks become a more prominent part of the publishing market, authors, publishers and digital distributors like Amazon are increasingly experimenting with new formats.

One of those formats is the ‘esingle’. As the name suggests, these are ebooks that are fairly short (usually longer than a magazine article but shorter than a full book).

Typically sold in the range of 99 cents to $2, or 70p to £2, the value proposition of esingles to the consumer is simple: quality content, no bloat.

At the beginning of 2011, Amazon launched Kindle Singles to better market the esingles format and promote it to customers. More than a year later, it appears that the experiment is working.

As reported by paidContent’s Laura Hazard Owen, who was given access to Kindle Singles data and authors, Amazon has sold a couple million Kindle Singles thus far:

Amazon says that in the 14 months the program has been running, it has sold over two million Kindle Singles. Seventy percent of each sale goes to the author or publisher, and Amazon keeps 30 percent. Amazon wouldn’t disclose its total revenues from those two million singles, but the minimum price of a Single is $0.99 and most are $1.99 (the author or publisher sets the price). So with an average price of $1.87 multiplied by two million, a rough estimate of Amazon’s 30-percent cut is $1.12m.

As you might expect, the amounts authors are making vary greatly. One author, Mishka Shubaly, has earned an estimated $129,000, while another, Frank D. Gilroy, has probably earned a more modest $17,500. But all of the authors interviewed by paidContent have one thing in common: they generally seem to like the Kindle Singles format and their experience working with Amazon.

The question for Amazon is how best to scale this opportunity. Amazon’s VP of Kindle Content Russ Grandinetti told paidContent that he expects Kindle Singles’ share of total Kindle revenue to “grow a lot”, but right now, the program is relatively small, with Amazon offering up just 165 Kindle Singles titles. It’s selective about what it publishes and is currently adding a small number of new Kindle Singles titles each week.

That has almost certainly helped keep the authors in the Kindle Singles fold happy, but it also gives competitors, namely traditional publishers and traditional media companies, time to warm to the esingles format themselves.