Was searching out a ref for the "any color as long as it's black" line from Ford, and found the the quote's context is even more useful.
The salesmen were insistent on increasing the line. They listened to the 5 percent, the special customers who could say what they wanted, and forgot all about the 95 percent, who just bought without making any fuss. No business can improve unless it pays the closest possible attention to complaints and suggestions. If there is any defect in service then that must be instantly and rigorously investigated, but when the suggestion is only as to style, one has to make sure whether it is not merely a personal whim that is being voiced. Salesmen always want to cater to whims instead of acquiring sufficient knowledge of their product to be able to explain to the customer with the whim that what they have will satisfy his every requirement – that is, of course, provided what they have does satisfy these requirements. [emph mine -mfn]
(Ignoring that the second and third sentences seem slightly at odds... Maybe the "complaints and suggestions" come from those who already bought, and who might require some work from Ford to get interested in providing feedback, rather than those who were just sales leads?)
Wow. That's from 1909. And it's as applicable now as it seems it must have been then.
Though let's not sleep on, "that is, of course, provided what they have does satisfy these requirements." This Ford dude seems to know what he's talking about. 😉