iPad has collected 22 percent of ebook sales since its launch and is about to get new features too. A PDF viewer is going to be thrown into the iBooks app later this month, and will be accompanied by new bookmarking and note-taking functionality. Yeah, they're basic enhancements at best, but we're still trying to wrap our minds around this idea that Apple is already responsible for nearly a quarter of all ebook sales. Then again, as Steve points out, a cool five million of the darn things have been downloaded in the first 65 days of the iPad's availability.
Update: Seems like even five mill ain't gonna be enough for Apple, which is set to massively expand its iBooks user base by bringing the app to iPhone and iPod touch users. You'll be getting the same note-taking, same bookmarking -- same everything -- just on a smaller screen, and at no extra charge. Users will be able to purchase a book on one device and then consume it across the full range of iDevices, with bookmarks and progress getting synced across the ether.