Earlier than expected, the Pottermore bookstore has opened, selling e-books of the entire Harry Potter series for the first time. The bookstore is unusual in a number of ways, not least because of the in-depth involvement of the author, J.K. Rowling, in the creation of the site. Her attention to detail, as well as the enormous clout that the Potter series wields, has enabled some ground-breaking changes to be made.

First, the biggest: the books will only be available from the Pottermore website – but will still be available on the Kindle. If you go to a Harry Potter book [2] on Amazon, you now see the familiar selection of formats: kindle, hardcover, paperback and audio CD. On the right hand side, however, where you would expect to see the "buy now" button, you instead see this:

And below the description is a new blurb:

Harry Potter Kindle books can be purchased at JK Rowling's Pottermore Shop, a third-party site. Clicking on "Buy at Pottermore" will take you to Pottermore Shop, where you will need to create a separate account. Like all Kindle books, books purchased from Pottermore are "Buy Once, Read Everywhere" and will be delivered to your Kindle or free Kindle reading apps.

When that description says "buy once, read everywhere", it means it; your £4.99 (£6.99 for the last four books) gets you a download that works on Kindles, Sony readers, and all iOS devices.

Those who buy it on a Kindle can use Amazon's automatic download feature, but on some other platforms – notably the Apple ones – it will have to be "sideloaded"; that is, the reader has to download the file and sync it with their device, like we all used to do for songs.

This is all an astonishing testament to the power that Harry Potter still wields. In order to get his books on their site, Amazon were prepared to break pretty much every rule they had set for all normal publishers. When Macmillan wanted control over how its books were priced two years ago, it ended up pulling every book in its catalogue [3] as part of the dispute. For the sake of seven children's novels, Amazon has given unprecedented control over to Bloomsbury and Rowling.

When the retailer eventually gave in to Macmillan and allowed it to pick the prices of its books, it made the policy global. That looks unlikely to happen in this case, but it's a rare breach in their armour. How other publishers respond will be important for the future of this young medium.

Hat tip to Paid Content [4]