How would you summarize the usefulness of this book? Is the world, or anybody's world, different or better due to the "use" of this book? How would the behavior of someone "using" this book change as a result of such use?
It helps you identify certain behaviors consistent with different classes, which helps you understand those in such a class.
I know I recognized behaviors in students, and it really made a lot of sense. For example, the poor value showing love by buying things. I always thought it was weird that some of the poorest students in my class had the nicest shoes. There is also a fear of kids doing better than their parents, which is completely different from middle class.