Sort of an interesting perspective in general.... http://www.marketingprofs.com/4/shaffer2.asp
I implore, however, that America do better a job than was tried with the metric system switch in the 1970s. Although that task may have been lacking, many Americans between the ages of 35 and 45 do know how many feet are in a kilometer due to the efforts of the Public Broadcasting System and its well-intentioned television program (or programme) Metric-Man. The only remnants of that failed legacy are thousands of signs sprinkled across the US, announcing the number of kilometers (along with miles) to an impending destination, along with an equal amount of Americans who actually know how long a kilometer actually is.
