If we're truly in the "attention economy," then a book like Hypnotic Writing could definitely be a competitive advantage for any of us.
I liked the concrete suggestions on how to improve your writing, the recognition that it's not a "quick fix" to do it, and that there are MANY complex parts to a well-written story.
What I didn't enjoy so much was that, well, to be honest, I didn't find the book all that hypnotic. I wanted to be enraptured the way I was with,say,Kite Runner, but that didn't happen. In fact, it's taken me about 3 months to finish it (ok, we had a baby-liveblogged birth here, but still).
At the end of the day, good writing, like anything else is a discipline. It requires practice, refinement, and hard work. That much, I got out of this book.
If you (or I) am not willing to make that investment, it's probably not worth the read.