From the Kindle Comunity forum:
Attention bloggers and website owners! Recently we announced that we are launching Kindle Previewer for HTML 5-a new way for readers to sample Kindle books through the web browser, anywhere they happen to be.
Now, we’re announcing Kindle Web Widgets — a free and easy way for you to add relevant content to your site and make money by advertising Kindle books.
Kindle Web Widgets are designed specifically for HTML 5 and CSS3, the latest generation of industry web standards. With embeddable Kindle Web Widgets, readers can preview books on your website, and then purchase those books directly from the widget.