There are some books that are available both as online versions or as a hard copy. Some newspapers are following suit with reduced production of hard copies to cut costs and to be in sync with their customers most of who have a prescence online. However, I suppose few things can replace the interactive and tactile utility of reading books offline. You only pay once and the item is yours for keeps but for online versions, an element of cost will always be there for example, to charge your laptop in order to access them. Which is more convenient?