I really like the premise of the product. A handy tool for gms on general plot ideas, twists, and other story telling tidbits. These provide a solid foundation that serves as a stepping stone to leap at a much greater and epic story of your own.
What I don't like about it is that even though it is supposed to be focusing on short stubs of plots, it feels rather short all in all. I could think of topics, ideas and bits to fill another book like that or maybe flesh out some ideas as examples or go into some tropes/clichés and how to avoid them etc. Good thing it was on sale, as I might feel a little underwhelmed by the length otherwise.
Otherwise, the writing is nice, scan/image quality is excellent and the usefulness of the book is undeniable.