I've read many books, as well as consumed a lot of other content on content marketing. I've also read Pulizzi's previous book.
This book is one of the absolute best on the overall strategy of your business as a content machine. You will not learn how to create a killer social media post, but you will learn a complete content strategy.
I am working in a startup now, and have also read a lot of books on that topic, such as lean startup. The big difference here is the audience focus instead of product focus, which I think is a winning long-term strategy.
A very interesting insight into the media industry, that I unfortunately believe is true in many cases. While I wouldn't think that every participant in the "system" is intentionally bad, I think Ryan Holiday shows well that the system is flawed and sick. The worst part about this book is that probably most of the things are true.
I have read/listened to a lot of books on social media marketing, content marketing etc. I didn't knew much about SEO though, this book gives a great overview of SEO, recommends strategies and tools as well as putting into the content marketing context.