Publishers won the throw down between Bezos and the publishing side of the business. Publishers assert that their expenses are marketing, promotions and other soft costs that don't get reduced by not printing to paper. Bezos point was that people are not going to convert to ebooks without a financial incentive. Hard to say how it will turn out. The problem newspapers are having is based on advertisers changing to digital more than consumers being opposed to paper newspapers.
Online ad sites are having a major lack of content problem. Without content ad metrics will not be good enough to justify the spend.
Printed books do not have a content problem obviously, however, there will be a push to put ads into books the same as all other online media. Then the question becomes consumer acceptance, will consumers accept advertising in a previously ad free medium. People born today may never know the difference.