I walked into this one with my eyes half closed, but had them opened pretty quickly. I wasn't sure what to expect, or what I would gain from this book - but it DOES pay.
Although the actual techniques in the book are not extensive, it provides a detailed insight into the workings of the body that most people assume they 'already know' about. Don't believe it for a second. This book can and (with persistance) will give you what it claims.
Note: This book isn't for the 'casual' one-night lover. It's aimed mostly at couples. So don't buy it thinking you can go out on a friday night and promise things to a prospective lover, because it doesn't quite work that way!
An excellent read and worth the money.