In a thoughtful essay about Amazon and digital publishing, thriller writer JA Konrath revealed Kindle sales figures for a number of his books--a rare disclosure from a published author. Along with his figures, the author offered helpful suggestions for authors uploading books to Kindle.

Konrath is the author of the Lt. Jacqueline "Jack" Daniels crime series and also publishes under the pseudonym Jack Kilborn. Since Grand Central published the Kilborn horror novel "Afraid" in April, the Kindle version sold 10,400 copies, each priced at $1.99. Konrath added "The List" to Kindle by himself in April, selling 1,612 copies at prices that ranged between $1.49 and $1.89.

Here's more from the essay: "With 1.5 million Kindles sold, I could sell 200 books per day, for 720 days, and still only reach 10% of all Kindle buyers. If we include all of the iPhone and iPod Touch owners who can download a Kindle ap, along with continued Kindle sales, I should be able to sell quite a few books before coming close to saturating this market. If the $90 per day trend keeps up, that's $32,850 a year. Not a huge amount, but not chump change either."