Writing a book on any aspect of the online world is problematic because it changes so much, which is why the people working with this daily enjoy it so much. There are many books explaining why the internet is important and why you need to be part of the hype - this is not one of those books.
What the team from Quirk have been able to do is create a solid book on eMarketing that will be useful for a long time, regardless of the continuous changes in this field. This eMarketing textbook addresses the core principles one needs to understand to use marketing principles effectively in the online space in a highly accessible format.