For those in the market for a new Kindle e-reader, Amazon also leaked its new Kindle Paperwhite, which is due to ship September 30.
Kindle Matchbook is similar to Amazon's AutoRip program which allows buyers of physical music to download a digital copy along with it. Though the music files were always a free addition, the bundled e-book versions will range in price from free to $2.99.
When Kindle Matchbook launches in October it will have more than 10,000 books eligible for bundling, and Amazon is expected to continue pursuing publisher support.
Further, the program will apply to a user's entire order history. A customer that bought Ray Bradbury's "Dandelion Wine," with their Amazon account in 1995 could use Kindle Matchbook to get a discounted digital version.
And ahead of any official announcement, Amazon briefly listed its upcoming second-generation Kindle Paperwhite on its website. According to the since-removed product listing, the traditional e-reader got performance upgrades that improve page turning, contrast and lighting.
New software features include Kindle FreeTime, which tracks progress and achievements for younger readers, and implementation of readers' social network Goodreads, which Amazon acquired earlier this year.