The trust equation

Maister, Green and Galford wrote trust down as arithmetic. Credibility, reliability and intimacy in the numerator; self-orientation in the denominator. The denominator is the one that does the damage, because every moment a customer senses the conversation is about your quarter rather than their business, the whole fraction shrinks.

The book uses it to explain a failure that surprises account managers every time. Promise a five per cent energy saving and deliver three, and you have helped the customer and damaged the relationship, because reliability took the hit even as value was created. The lesson runs through value capture: a promise you can prove you kept is worth more than a bigger promise you cannot, and the baseline you agreed at the start is what makes keeping it visible.