Sorry to say that this book isn't available in ebook format, yet.
I have been waiting for this book as well as "100 Years of Solitude" by Gabriel Garcia Marquez to become available.
"The Crimson Petal and the White" is published by Harvest Books, which is an imprint of Harcourt Books. The decision to go digital would be between them and the author. You might want to check with them as it might be the type of feedback they need. http://www.harcourtbooks.com/AboutPublisher/
"100 Years of Solitude" is published by Perennial, which is an imprint of Harper Collins. Might want to check with then too at: