There's something new launching in October from Amazon, which is called Kindle Matchbook. I received an email about it, and signed up straight away. Essentially, it's an offer that bundles print books and ebooks.
The idea is this. If you buy, or have bought in the past, a book in paperback from Amazon, you can buy the ebook equivalent for a discounted price - the discounted price being 2.99, 1.99, 99c or free.
The best part about this is the fact that it applies to books you've bought from Amazon at any stage... so if you want to grab your favourite paperback for your kindle, it will cost you no more than half the regular purchase price of the ebook.
I love this, and for my paperbacks (which vary in price from $7.20-$9.99) I've set their ebook equivalent Kindle Matchbook price for 99c.
A note for self publishing authors : The 99c price point for authors usually gives a 35% royalty rate, with the 70% royalty rate reserved for ebooks sold at 2.99 and up. On signing my print books up for Matchbook, it appears as though the royalty rate is closer to the 70% rate, which is the rate my ebooks qualify for at full price.
So - Kindle Matchbook launches in October - keep an eye out for it!