Here's why I think it is revolutionary for elementary students:
It has truly become a means of sharing books and recommending to a much wider audience. The visual aspect is powerful, and it's very easy for children to navigate.
On their own, students are discovering that when someone recommends a book, you can simply add the title to one of your shelves. My list of 'want to reads' is growing immensely, directly due to the kids' recommendations.
Most powerful for me is when I see someone write a recommendation and shortly thereafter there are a number of kids who move that recommended book to their list of 'want to read' books. A culture of sharing good titles is growing .

Admittedly, a big part of me was worried about someone being inappropriate. We had a few small incidents in the beginning, but it shows me how important it is to talk to kids about the importance of developing smart online habits. What you post is out for your peers (and your librarian) to see...

Best part of the whole thing--it's not just the voracious readers who are into this. The quieter ones are also finding their voices.