In general this book is a collection of several different ways to teach a class with little to no preparation.
Daniel Marques has written quite a lot of books in areas from "Apocalypse: A message from the Universal Alliance of the Intergalactic Confederation regarding the End of the World" to "Why You Should Believe in Me." I haven't read any of his other books, but I do tend to think, "Jack of all trades, master of none." I could be wrong. It seems he has experience needed to write a great book. He has been a teacher in primary school as well as high school.
In essence, he wrote this book for those days when a teacher just is not feeling up to teaching a "real" lesson and can fall back on some of these "lazy teacher" classes instead.
Here's a sample page from the Kindle App on my tablet.As you can see he does offer a lot of variety, which I appreciate.
Overall, this is not the best book I've ever seen on teaching. In fact, I don't think it would make the top 50 list. I think that learning a few simple no-prep activities, or putting some serious planning into "backup" classes that can run themselves is the best way to do things. However, if you are a teacher looking for a bunch of ideas (some better than others) you can go to when you've had a bad day, this is the book for you!
Would you buy this book? Or what activities do you save for days when you just can't hold a normal lesson.