What is the trust equation?
The trust equation is a model in which trustworthiness equals credibility plus reliability plus intimacy, divided by self-orientation: T = (C + R + I) / S. It comes from The Trusted Advisor (2000) by David Maister, Charles Green and Robert Galford. Credibility concerns what a person says, reliability what they do, intimacy whether others feel safe confiding in them, and self-orientation whether their focus is on themselves or on the other person.
Why it matters to a revenue leader
Self-orientation sits alone in the denominator, so a seller visibly focused on their own quota erodes trust faster than strong credentials can build it. For a revenue leader, the model gives coaching language that goes beyond product knowledge. A rep can be credible and reliable and still be distrusted if every conversation drifts toward the deal. The equation helps a manager name that problem without making it a personal attack.
Example
A sales manager reviews a lost renewal at an industrial client. The rep was knowledgeable and always on time, but the client's feedback says every meeting ended with an upsell pitch. In the coaching conversation, the manager uses the trust equation to name the issue: high credibility and reliability, undone by high self-orientation. The rep agrees to open future account reviews with the client's results before any new offer.
"Would our largest customers say our reps focus on the customer's results or on their own quota?"
Sources
- The Trust Equation - Trusted Advisor Associates checked 9 Oct 2026
- The Trusted Advisor - David H. Maister, Charles H. Green, Robert M. Galford - Google Books checked 9 Oct 2026