tl;dr
I'm experimenting with KDP for niche technical programming books.
The Marathon Begins
About a year ago I decided to write a book. I didn't have a story to tell. I wasn't planning on making money. My impetus was to prepare for a 3 hour long conference tutorial I was giving. Rather than spend my prepartion time creating slides and going over them, I figured I'd write a book covering the material. It worked out pretty well. Except the book's release was delayed by about 5 months. Yeah, writing a book takes a LOT more work than I would have thought. In the mean time I drafted "the Python book I wanted when learning Python" and made it available as an epub, which I put on Barnes and Noble, a mobi which was sold on Amazon and a bundle containing the two e-books formats as well as a pdf that I sold on my site.
With the release of the Kindle Lending Library, where Prime members can borrow a book per month, there have been reports of how KDP can boost sales. These posts seem aimed at fiction (as does most of the self publishing world). There aren't any reports of technical writers making tons of sales (barring 37 signals). So I'm trying experimenting.
KDP Select for Technical Books
Beginning 10 minutes ago, both of my books are only available via Amazon. I'll be reporting back what happens. I'm not expecting a miracle, nor am I expecting to quit my day job. I just want to see if the Lending Library expands my reach.
If you are in a similar situation please feel free to comment below. If you are looking for an epub or pdf, sorry, for at least 90 days I'm exclusive to Amazon.
Feel free to follow me on twitter for progress.