… is from page 178 of my colleague Dan Klein’s March 2001 Economic Affairs article, “The Demand for and Supply of Assurance” – which is revised and reprinted as chapter 9 in Market Failure or Success  (Tyler Cowen & Eric Crampton, eds., 2002) (original emphasis; citation omitted):
A machine-tool company such as Black & Decker makes hundreds of different products, but its customers will generalize to some extent about all of them based on their experience with only a few. By enlarging its product base the company creates frequent dealings with many of its customers, giving them a better opportunity to evaluate its trustworthiness. In this way, Black & Decker becomes a provider of assurance, as well as tools. The inventor-genius may create, de novo, in his basement workshop a fantastic new tool, but it is not a great product until it is combined with assurance.