Google Play : Java Glossary

Google Books evolved to a commercial eBook store with links to affiliate print bookstores. Then it split off as Google Play as a commercial eBook, free book, magazine, Android app, device and movie store.

Idiotically, you can’t search by ISBN (International Standard Book Number).

Google ebooks has a JSON-based API (Application Programming Interface), similar to, but simpler than, Amazon’s AWS (Amazon Web Services) to interrogate their database of books. Like Amazon, they use their own book id numbers instead of ISBNs (International Standard Book Numbers). You use Google’s OAuth2 protocol to identify your app as friendly to Google. It looks like it requires human intervention to login. Gag. I don’t if the two will be integrated or Google Book will be dropped. There is an affiliate program, but it is available only to big players. The API is more open, however. Google rudely dumped previous affiliates after they had invested in writing code the API. The API is such a production, I doubt many non-affiliates will bother with it.