The Pottermore shop is NOW OPEN! “Potter” eBooks are available
The Pottermore Shop is the only place to buy the Harry Potter eBooks and digital audio books, and it is now officially open.
From the Pottermore Shop release:
For the first time ever, you can download the Harry Potter eBooks and digital audio books and read or listen to them on the device of your choice.
Get ready to discover and explore the stories in a whole new way: shop.pottermore.com