Really really good and helpful. This is a short book that is full of helpful rules (of-thumb of course) and anecdotes that further your understanding of how to deal with customers. The author has an understanding of why and how customer interactions fail, and what fears are involved. It has solid guiding principles like "Lean in and acknowledge your customer", while also talking about deescalation and how to deal with terrible people. I liked the point that all interactions go smoother once you're confident that you can handle worst-case interactions.