People are already using books details as the place for book reviews, adding some books as inventoried despite the fact they don't have it physically, simply want to share an opinion on it. The problem with this way to do is that it gives a confusing information (adding it to your inventory despite the fact that you don't have it) and in case the book is given or sold, the description will disappear.
Ideas to explore:
- give reviews a CC-BY-SA license by default
The Lib.reviews project is building a free, open and not-for-profit platform for reviewing. They're in early stage, but maybe there's something to explore here.