Hacker News Books

That sounds really great: however, how much percent of the books have a Kindle edition?

I have heard this question asked rhetorically approximately 15 times and nobody ever seems to be willing to get their hands dirty.

The New York Times bestseller lists both identify and anoint winners in the publishing markets, which are winners-take-most games where the head vastly outsells the tail. You can read them online. You can also search for books on Amazon. Combining these two processes in a revolutionary way produces the following:

  Fiction: 
    The Lost Symbol (Dan Brown): KINDLE
    I, ALEX CROSS, by James Patterson: KINDLE
    UNDER THE DOME, by Stephen King  -- no kindle
    THE HELP, by Kathryn Stockett: KINDLE
    U IS FOR UNDERTOW, by Sue Grafton: KINDLE
    PIRATE LATITUDES, by Michael Crichton: KINDLE
    FORD COUNTY, by John Grisham -- no kindle
    THE LAST SONG, by Nicholas Sparks -- KINDLE
    THE CHRISTMAS SWEATER, by Glenn Beck et al -- no kindle
    THE LACUNA, by Barbara Kingsolver -- no kindle

So, to a first approximation, I'm going to guess that in excess of 60% of titles sold in the United States weighted by sales have a Kindle edition available.

Feel free to do the gruntwork for non-fiction. I think you will find pretty much the same,