copy per student for in class use. this worked pretty good for my daughter in junior high, when her school tried this. we always had the book she needed at home. however, this could be more expensive for schools because they need to buy more books in order to keep 30 or so books in the classroom.
neat to hear that some books would be available for rental for a certain time period. i know some libraries are providing this service for many books too. i personally haven't done so yet, but would like to try this. i think this would be good if the schools are able to provide e-books 