If you’re old enough to remember the Pet Rock craze, then you have had an important lesson in the literal value of a trope. Personfication is a trope because it represents non-literal language: not literally true, but not a lie, either. Tropes play pretend; and what plays pretend better than a Pet Rock?
Pet Rocks were the brain, um, child of a California ad exec named Gary Dahl who came up with the idea in 1975. Each rock sold for $3.95, complete with a box (it had air holes so the rock could breathe), straw, and a thirty-two-page manual with instructions on teaching the rock such tricks as “stay,” “sit,” and, with an assist by the owner, “attack.” The fad lasted half a year; Santa brought us one for Christmas and we set it free in the backyard.
Dahl used his profits to open a bar, which he ironically named after the anti-alcohol crusader Carrie Nation. Leave it to an advertising man to make a fortune out of tropes.