Lets start with the good. Its broad and thorough, covering a range of topics.
If you are looking for a way to understand the basic (I underscore BASIC) economics of EC then this could be for you.
If you are in the business already, and looking to get some depth to your fundemental understanding of how to make money in EC, lets say for a business plan.. You should look somewhere else.
The book covers very elementary topics, and is not appropriate unless you are an undergraduate (e.g. what is a digital certificate, what are the economies of scale in software).
My feedback to the authors would be to take some real business models and include them as case studies. Of course since there are so few companies in the black, perhaps that would just scare off all the folks that read it from starting a business :-)