I think the ideal reader for this book would be just starting to get involved in some sort of activism, either a starting a cause or joining an established one. It gives just the kind of high-level orientation they probably need. Warning: it isn't more than a high-level orientation and won't tell you everything you need to do!
If the reader is more experienced, the nitty-gritty practical details are probably going to seem too general, too vague, or too incomplete. The book tried to address an international readership and all varieties of activism. Experienced activists probably (hopefully) already have a good grasp of specific laws and strategies that apply to them. On the other hand, I kept wanting to share this book with some of my activist friends because the author is brilliant at dissecting the philosophical and conceptual issues which seem to keep giving them grief.
I'm not officially involved in any activist movement (yet, who knows?) so I was reading for general interest. That made a few chapters seem a bit dry, but overall, the conceptual and analytical clarity made it interesting and informative.