I just took a marketing class and was really impressed with the USP concept. When I tried to create my own, I hit a wall. Just like your chiropractor, the things that I thought set me apart were really the same "benefits" that my competitors offered. I have since started working with my marketing teacher to develop my USP and feel that I am on the right track.
Your article is right on—the steps are achievable, easy, and best of all FREE. Creating a USP is crucial to success in business—especially small businesses. They usually can't compete on price or convenience so they must find (or create) something that will set them apart from the competition.
One point I would add, is to make sure that the USP is customer driven. It is great to tell your customers why you are different but more importantly you must tell them why it matters to them. When creating a USP, think benefits rather than features.