It is one thing when a company gets an upcoming feature or product leaked. It is another thing entirely when the company itself leaks the upcoming feature or product. That appears to be what happened late on Friday with Google Play Books.
Both online and in the Android app, a banner in the Play Books store promoting the coming of Audiobooks to the store and a 50% discount on your first purchase. I, unfortunately, didn’t capture the banner but the folks over at 9to5 Google did and you can see it here.