Word of Mouth Marketing — How Smart Companies Get People Talking
by Andy Sernovitz

This was a fun book that you can read in 90 minutes and has some good pointers about word of mouth marketing. Sernovitz is a smart guy and the book is worth reading if you are not yet convinced that buzz marketing is powerful. Personally, the book would have been more interesting if it had more examples and more details of case studies of companies that used word of mouth marketing successfully.