This statistic is coming from Amazon re: Amazon, it is not encompassing the entire book industry. Even though Amazon has quite the market share when it comes to books, they don’t have all of it!
Amazon is, for lack of a better phrase, the “Wal-Mart of the internet” and people treat it as such. When I want to buy a book, I do not normally think to purchase it off of Amazon, rather I venture to Barnes and Noble or an independent book-seller. Especially now that Borders is gone and B&N is the only major chain selling books, I will try to take as much of my business to Barnes and Noble as I can.
How does this affect the library? So far it hasn’t. We still have people clamoring for the newest paper copy of James Patterson’s book of the week and I don’t see it affecting rural/semi-rural public libraries in the immediate future.