If you want a book about writing letters and sending pics to the letters pages of magazines, this book is fine and full of inspiration, but you probably won't make much money, since the majority of magazines that used to pay out quite a lot for letters and readers pics, have cut costs. Many now only pay for the 'best' contribution (e.g. star letter/winning pic) in each category.
Incidentally, Full House magazine went out of print in the spring of 2013 - almost a year before this was published. The author suggests that you write to them. Good luck with that! I did expect something a bit more than fillers for letters pages, but it's nicely written and upbeat style, so if that's what you want, it's fine. Cheap and cheerful.