Been on an Audio-books kick with my long commute each week. I figure I am in the car about 3 hours a day and I get so tired of listening to the same news over and over again.
Just finished a “Free” download from Audible.com called “Free- The Future of a Radical Price” by Chris Anderson the editor of Wired Magazine.
The book is about the economics of “free”. From a B1G1 business plan to digital free. He breaks down how huge companies such as Microsoft and Facebook allow for “free”. The biggest business model that is spoken about is the “Freemium” the model that 5% of your customers will support the other 95%, meaning if you have a free version and a premium version that an individual can purchase, in bits, not atoms that 5% of those will become premium members and in turn pay for the amount of receiving that service to those who do not pay.
I am not an economist, I have not taken financial coursework, but the audio-book was great to listen to and I believe I learned a bit about the economics of “free”.
Chris Anderson wanted to be able to test the “free” theory so he made the paper copy of this book for sale, while giving or “gifting” the digital format.
Very much recommended.
NY Times Book Review- written much better than mine 
FREE audiobooks on loan from the worcester public library
http://worcpublib.org/about/eAudiobooks.html