How to Write a Business Letter
The pattern
This still is filed under Direct-from-the-founder letter.
Define
A letter in one person's voice, written as if to one reader, signed by the person who owns the outcome.
Mechanism
Personal authority. The signature is the proof. The tone is the brand. A committee cannot write this and keep the mechanism.
Verdict
Trust sits on a person
Why it works
The teaching is done by contrast, not by rule. Pairing a bloated sentence with its cure on the next line makes the edit self-evident and gives the reader a pattern to apply, which is why that chapter is the most copied part of the book. The model letters are organised by the job to be done - ordering, dunning, adjusting, recommending, selling - so a correspondent finds the situation rather than the principle. Wiers frames courtesy as commercial self-interest by tying every letter to the second order rather than the first, which converts manners into a measurable thing.
Steal this when
Reach for this structure when you are teaching a craft to people who will use it under time pressure: set the wrong version and the right version adjacent with no commentary, then file the finished examples by the situation the reader will be in, not by the principle you want to teach.