How I Use It
As a Language Arts teacher, this is a good product to use as part of a book discussion or book talk. You can set up groups that are private (although you can choose to make them public). Keeping in mind that this wasn't designed as an educational tool, it has potential, especially as an extension of the classroom and as a way to let students share online vs in face-to-face discussions. Adding books to the group shelf takes a few steps, but as a way to have students interact while reading, it does what it's designed to do. Setting up discussions is easy, and there are ways to control what students/members can do in the group vs. group administrators. One downside for me: it requires an amazon.com account (which you can build with any email address).
If having online discussions is an important part of a teaching practice, this is a good tool. It can give students a chance to write critically, read what a review looks like, and learn about the pros and cons to user-generated and user-edited content. I liked the ease of setting up the group and the options for members, although having to email invitations could be a downside for those schools/districts where students aren't given an email address (this would also be problematic for account set-up). It would be nice if you could also invite students to a group via code or group key. Because it's browser-based, that opens up some opportunities for access from anywhere, along with read-aloud supports if using Chrome.