Google is rolling out an update to the Google Play Books app today, and for the first time in ages there's a notable new feature. It's called Discovery, and it helps you discover new stuff to read. As is the case with a great many Google features, this one is available in the US only at first.
The Discover section of the app is accessible from the navigation panel. The content it shows you is based on your reading history. It includes content from the web like best-of lists, reviews, and even some videos. A weekly highlights section will also provide access to the most important content featured in Discover over the week.
Google is actually producing content for Discover too. There are a number of Google Play Books editorials that cover various topics with links to the books discussed. Sometimes these take the form of author interviews, and others they might be an essay by an author or some other person in the literary world. You'll need the latest version of Play Books (3.10.19) to check out Discover, which is available on APK Mirror.