My books have just finished their first enrollment in the Amazon KDP select program, so it is time for my review of the program.
Quick summary first: Amazon gives new authors many tools to help promote their books and make money from them.
Now for the long winded details. I would say it is definitely worth using for a new unknown author for a few reasons:
1. All books in the program automatically get put into the Kindle lending library, which means people can read your book for free while Amazon pays you a fraction of a cent per page the first time they read it. Currently the amount they pay is around .0042 cents per page, which seems horrible until you consider that if someone reads my entire book in the library I actually make more money than I would if they bought it!
2. In each enrollment period you can set up one limited time offer for each of your books: Either a sale countdown or a free book giveaway. The giveaway is great for making an audience if you plan on writing more books (which I do).
3. You can place your books in an ad campaign which will show your book to readers as an ad in their search results or on the book details page of other books they view. When they show up is based on various criteria you select. For example: I target people who are interested in science fiction and a few sub categories of science fiction. To get your ad to appear you place a bid and set a limit of how much to spend during the time the ad will run. This really helps people find the books written by an unknown like me. It take a lot of tweaking, but after a month or two, the ads really start bringing in readers.