Many authors and publishers use a company such as PublishDrive or Draft2Digital to handle their distribution to smaller ebook retailers. They trade a small cut of their revenue for less hassle in managing their ebook offerings across multiple smaller ebookstores whose sales do not justify a direct relationship.
One would think that it is a good deal all around. Google, however, would disagree.
I’ve just heard about a policy Google started enforcing a couple months backs. It seems that Google now wants all authors and publishers with titles in Google Play Books to have a direct account with Play Books.