Truth is stranger than April Fools.
Following up on what was expressed in the Shelf-Awareness April 1st edition as the "buy or bye" button
...key among the changes: all book titles listed on Amazon will have "bye" buttons next to the "buy" buttons, only one of which can be activated at a time...
Penguin and Amazon have failed to reach an agreement over terms of sale. As a result, Penguin e-books released beginning today will not be available at the Kindle store. E-books released prior to April 1 are still for sale at the $9.99 price.
Penguin CEO David Shanks explained that Penguin has reached new terms of sale agreements with a number of e-booksellers, but not Amazon. "Our conversations with Amazon are ongoing and we do hope to continue our long-time relationship with them," Shanks said. Shanks noted that new Penguin e-books "are available through Barnes and Noble.com, Sony, Kobo, eBooks.com, reader applications on the iPhone and soon on the iBookstore for the iPad. Additionally, we're working with our digital delivery partners (Ingram, Overdrive, and Baker & Taylor) to make your eBooks even more widely available."
Publishers Weekly reports.