I have delayed publishing my work through the Kindle Direct Publishing in part because I hoped that Smashwords would close a deal with Amazon. It does not appear that will happen any time soon, because Amazon has no real incentive to distribute for Smashwords when it operates its own system for publishing e-books in the Kindle Store. Meanwhile, I'm missing out on a huge and expanding market.
I had looked at KDP when it was first announced, but I was intimidated by the instructions for converting the book to the Kindle format. Recently, fueled by the awareness that I'm losing out on money by not publishing on Amazon, I screwed up my courage and tackled the project of uploading Sisters to the Kindle store. I managed to convert and upload it after only four tries. (That's very good for me.) Ultimately, I'll make less per e-book sold on Amazon, but I'm not selling anything there now, so I'll be ahead no matter what.
I'm doing pretty well with sales on Sony and B&N. It doesn't cost anything besides a few hours of my time to do the formatting, and the rewards from selling on Amazon could be pretty good. Anything greater than zero is 100% profit for me.
Now the question is: do I want to go to the effort of converting all my other stories and publishing via KDP also. While I'm deciding about that, Sisters is available in the Kindle Store and on Smashwords.