I can't remember who said it, but a customer buying a shovel is actually buying a hole. The customer doesn't care about the shovel he / she cares about solving a problem.
Bad salesmen get caught up in the product. Good ones usually focus on the person buying. Also, focusing on "the hole" gives a salesman more latitude to influence the buyer's reference products, prices and general buying psychology. This last point is only really important because people do not often buy holes, they buy shovels. In a buyer's mind, a shovel has price, some features, a lot of reference and comparison points. Holes don't. The involve labour and blisters and shovels and no point of reference. This is useful to a salesman.
Basically, people will have completely divergent prices they would be willing to pay to get a hole, depending on the instrument used to dig one for which they will be paying. This is the principle at work when a user won't pay a 99c for online content unless it meets some incredible standard, but will walk out of a newsagent with a stack of magazines without much of a fuss.
That's why there is a fundamental difference between selling an "online course" and an ebook, even if the content is similar. Books have a price. $200 is a very very expensive book (ripoff!), online courses don't have a defined price.
So... uhmmm I disagree sir! (glove slap, pistols at dawn, onlooking maidens) People do buy shovels.
In the book, Norman says exactly the same thing. That people are looking for something to achieve some goal, and the hole and, consequently, drill are just means to that end.
Of course the spirit of the quotation is different. It means "serve the ultimate goal, not the task chosen to achieve that goal", so it encompasses this with some degree of rhetorical flourish.