Amazon has an under-publicized program called Matchbook. By enrolling in this program, a publisher can offer a Kindle book at a steep discount to buyers of the print format. You can see the books in the Matchbook program here.
Think of the possibilities. You can buy books as Christmas presents and then download a Kindle copy for yourself. Kinda like two for one. This might be a great idea, but you may not want to buy your great aunt Sex Love Repeat by Alessandra Torre. Maybe Johnny Carson by Henry Bushkin would be more appropriate. Or perhaps she would prefer Tempest at Dawn, since all of my books are enrolled in the program at 99¢ for the second copy in Kindle format.
It's only two weeks until Christmas, so you may want to use my great idea to finish off your shopping list.