Peter writes, "Macmillan has partnered with ebook bundling start-up BitLit to offer readers who own a print edition of Tor/Forge titles the opportunity to download a DRM free ebook edition using the free BitLit app (available for Ios/Android)."
Macmillan is the second of the Big Five publishers to join the service. HarperCollins, the first of the Big Five to join, now has over 9000 titles available through BitLit.
Unlike Amazon's Kindle Matchbook bundling program which requires that the print edition be purchased through Amazon.com (and only provides a DRM'd eBook for the Kindle platform), BitLit allows readers to get the digital copy of a book regardless of where or when the purchased the book.
The bundling process on BitLit involves downloading the app and taking a picture of your bookshelf (a "shelfie"). The app will identify all of your books and tell you which books are eligible to bundle (with their current publisher partnerships BitLit estimates that about 10% of the books on an "average" shelf will be from their partner publishers). To claim the eBook of an eligible title you'll need to take a picture of your name written on the copyright page (ex-libris stamps and bookplate stickers are also supported for those who have messy hand writing).