I enrolled my collection of short stories, Numbers Plus Four, in the Amazon KDP Select program. What that means is that the book is available to borrow for free under the Kindle Owners' Lending Library. Also, there will be five days when the book is free to buy for everyone! And guess what, the first free period starts tomorrow! If you visit the book's Amazon page between tomorrow, Jan. 9, and Wednesday, Jan. 11, you can download it without charge!
I've heard some amazing results from other authors who tried the KDP Select program, so I thought I'd try it too. The drawbacks that I can determine are that the author makes no money during the free period, and the author has to make the book exclusive on Amazon, i.e., the digital copy can't be sold anywhere else. These seemed like reasonable trade-offs to me. Depending on how it goes, I may also enroll George and the Galactic Games in the program.