You'll recall that some years back I set out to write a principles text. I've finally done it. In addition, I think this is the first book for the mainstream intro econ course that is available as a free download.
The publisher, Freeload Press, will earn revenue by selling advertising on the website where the book is distributed. Also, when you download chapters (as PDF files), the first couple of pages might be advertisements. There is a short registration form, but downloads are free. If someone wants an advertising-free, black-and-white paper copy, it's available for $30 at the website ($20 for a micro or a macro split). There will soon be a workbook up on the website to accompany the text, and a test bank is already available for instructors. The website for Freeload Press is http://www.freeloadpress.com.
Is an advertising supported approach a sustainable business model for a textbook company?