Someone
may have mentioned a promotion like this that Amazon had before (it
may have been me.

). Anyway, I'm not sure of that, and even if I or someone else has mentioned this before, it bears repeating (maybe).
Here's how to get three
free books. Point your web browser to
this Amazon URL. You'll see thumbnails of the covers of about 14 books. Buy three of them--they are all
99 cents each. Amazon will issue you [I]a credit of $3[I].
You may be saying to yourself, and maybe to someone else, too--yes, but that's a
credit, not 3
actual dollars! Well, you are going to buy something from Amazon before January 31 aren't you? Three dollars credit or $3 cash--what's the difference?
Make sure that you read all of the "conditions" (they're not very onerous, for the most part), especially the ones above the thumbnails (the rest of the rules are below the thumbnails).
Of course, the drawback is that, out of only 14 choices, you may not see any, or but 1 or 2 books, that interest you. Still, you want to buy 3, even if that is the case, in order to get the credit. Too, as one of the conditions points out, the $3 credit is good (only) for "the purchase of select Kindle Exclusive books." Unfortunately, we don't get to see what the Kindle Exclusive choices are going to be.
I didn't check any of the books, but one or more of the ebooks may have Whispersync deals (I couldn't find a way to sort or filter them out of the ebook choices), and one or more of those may have really well-priced ones, what with the ebook component being only
99 cents.
All of the books are fiction, so we non-fictionistas need not waste our time. That is, unless we want the 3-cent credit for the choice of some Kindle Exclusive books.