The "read" status I've given this book is purely for convenience: it is one that anyone who enjoys the nuts and bolts of literature as much as the actual product should always have on hand, whether to help answer a specific question, satisfy a vague curiosity, or use lucky dip style to discover something new about literature, and, by extension, the world.
This book represents a body of knowledge approached and collated by the same scholar, making for a compact, easily accessible, and, best of all, integrated, resource - and in that respect is better than trying to pick through the internet for the same definitions.
If you want quick but accurate descriptions of literary terms, nevertheless with some depth, and pointers on where else to go, this volume, while certainly not cheap, is definitely worth it.