This book won't tell you how to make your manuscript a blockbuster, record seller in the veins of 'Fifty Shades of Grey' or 'The Da Vinci Code' and the like. This book also really won't tell you much of anything else, either. A problem with having more than one author can be especially apparent when the writers have different styles, strengths or just plain ability to write.
I had been super excited by this book that (I thought) would help me understand why some books fly off the shelves. Bestsellers are rarely worth the hype in my opinion and I often avoid them. What is it that helps these books appeal to the masses? Word of mouth? The plot? Writing? Characters?
Honestly, it was hard to tell from this book. There appears to be some attempts at using cold data analysis (word usage) but there are also pieces that aren't quite as quantifiable in terms of numbers such as name recognition (Nora Roberts for example) or topic (certain subjects like Abraham Lincoln to stories about dogs are often sure to move numbers).
The criticisms and negative reviews are on target. I had not realized this book had more than one author and it shows. It veers from being relatively readable to academic dry text. It is repetitive. In the end I became increasingly confused as to how it made it past an editor. This would have read MUCH better as a longform piece of journalism, a blog, etc.
There might be interesting bits in here but overall I found it to be a waste of time and didn't really answer my questions. There are also spoilers for many books (in discussions of plot and whether that plays a role in what sells better), so be warned if you don't want to know. Overall I'd skip this one.