Amazon has expanded its Kindle web app so consumers can purchase and download entire books onto the devices of their choice - a laptop, say, or a desktop. The point is, there is no additional software to download to make the purchase - nor is it necessary to own a Kindle. Another change lets blogger and e-tailors sell Kindle books directly from their websites. There are a number of reasons why Amazon took this step - the long-foreseen launch of Google ebooks being one; the ever encroaching iPad another. The point is, ebooks are migrating to an open web strategy not only for Amazon and Google but also likely their competitors such as Barnes & Noble. And as more companies move in this direction, advertisers are going to going to follow suit, intrigued by the promise of a brand new online medium.

The Wall Street Journal raised this possibility in an editorial earlier this year: Publishers, seeing profits drop as more and more consumers choose to read cheaper books on electronics devices, already believe that advertisements may be necessary to save book publishing.

This new environment will likely start off with free samples of digital books that include ads, the Journal said. Then, the issue of hardcover vs. paperback books will give way to ad-supported or ad-free books. Publishers will begin to evaluate books based not on how many are actually sold, but on how many are read - meaning an unread book will become less profitable to a publisher. And writers and agents will have to negotiate whole new arrangements with publishers.

By moving its Kindle app to the web, Amazon will help marketers jump several hurdles that were between them and the Journal's scenario - the primary one being, of course, the proprietary systems and hardware that have dominated ebooks up until now.