A book about speaking has an obvious test to pass, and How To Speak So Others Listen submits to it directly: Maryam Pasha narrates the recording. Advice about holding an audience, delivered in a voice that could not hold one, would be its own refutation.
The triple shelving tells you the intended reach. Business and careers, education and learning, personal development. Speaking well is a professional skill, a teachable craft and a matter of nerve all at once, and our catalogue declines to pick just one of those.
Everything else remains outside the scope of this page.