Just recently, my book, Non-Federal Censuses of Florida, 1784-1945: A Guide to Sources, came out in a Kindle edition from Amazon.com (through an arrangement my publisher, McFarland, has with Amazon). I am ambivalent about this.
On the one hand, it is the current trend and, I suppose, the wave of the future. E-books are here to stay, I know. And I am getting the same royalty rate on Kindle sales, just not the same amount, of course, because the Kindle edition costs less than the print edition. Of course, the Kindle reader itself is not exactly inexpensive, which has an effect on the dissemination of the electronic texts made for it. As the technology develops, as with other electronic innovations we have seen over the past few decades, the price will come down as they become both more common and more sophisticated. E-books do have the advantage of not requiring bookshelf space.
On the other, I am an old-school sort of person who prefers the feel and versatility of a print book. I would not read a Kindle or any other e-book in the bathtub, for instance (though I rarely read in the tub because I prefer showers). I cannot really mark in an e-book (though there are, I know, provisions for making some sort of notes and comments in them) like I can in a print book. As a historian, I read a lot of histories and related works, and I like to argue with my texts by making marginal comments. Print books are not at the whim of ever-changing technology and the problem of "platform creep." And print books are easier on my old eyes.
I also remain unconvinced that e-books are piracy-proof (though, come down to it, print ones are not completely piracy-proof, either). I suppose it is a toss-up, and I have to say I am in favor of whatever method will result in sales of my works, of course!