I can buy a new release by Frederick Forsythe in hardback or I can wait for the paperback version. Also I can go to my library which will have a certain number of copies, and put my name on the waiting list.
Now if it's available as an ebook from the library, why would I buy it when I can read it for nothing as soon as it's released even if it will expire after a certain period ?
His latest work, "The Cobra" is now available for download from the kindle store at Amazon.com for US$12. I can get it right now, without leaving the house, for less than half of what a bookshop will be charging when they get it in. What happens if it's available in libraries at the same time ?