While I liked your review, and others, I wasn't too happy with your topic line " the only self help book worth reading".
While I don't want to take a book review too seriously, I think the above needs expanding on, though my comment isn't "aimed at" you, it's more general to the whole issue. What constitutes a self-help book? This needs some attempt at a definition!
I am reading a Kabat Zinn book on mindfulness meditation, having already benefited from Lovingkindness by Sharon Salzberg, both dealing with Buddhist concepts. Are these not self-help?
And what about Self Compassion by Kristen Neff, itself a critical appraisal of the Self-esteem industry?
I think we need to be careful of sweeping statements, there are others out there coming to this area for the first time and seeking help with their suffering, and many books which can be considered "self help" will help people start their journey to a happier life. And of course it is a journey, no one book will be The Answer.
What do others think here?