This particular book gives good advice on trick selection, how to incorporate company messages into magic presentations and other general advice for a magician who wants to work trade shows. However the most valuable component of this book is that unlike other books of this kind this one concentrates on how the performer gets the booking in the first place.
The author describes a system he uses combining direct mail and cold calling. He tells you how to get the names to build a mailing list and mentions sources galore where you can find contacts to help you in your search for a trade show booking.
I would say that more than half the book is taken up by advice on marketing your services as a magician and that can only be a good thing. I would recommend the book for that alone. To be frank I personally don’t use most of what is described to market my services but that doesn’t negate the usefulness of the techniques to others.