Selling Hope

One of my old golf coaches said something to me once that has always held true. He said, more or less, that if you make something--regardless of how ridiculous, outlandish, or helpful it actually is--that promises to take strokes off of your game, the public will beat a proverbial path to your door. What is it about golf that has created a cottage industry of score-improving devices? Are there other activities that are untapped for this type of marketing?