Calvin Coolidge was the 30th President

You'll be surprised to learn advertisers spent $7.6 billion on billboards last year (a sum equal to the amount Americans are about to spend on legal marijuana―but that's another story).

Year after year, the billboard spend increases.

That's because billboards work.

In 1969, the trade association for billboard companies asked its members to join in an experiment meant to prove that very thing. Without fanfare, thousands of billboards with the slogan "Calvin Coolidge was the 30th President" appeared nationwide. Public awareness of Coolidge rose eightfold―from 4 to 39%―as a result.

Six years later, a similar experiment used the reigning Miss America, Shirley Cothran. Her name, face and title appeared on 10,000 billboards across the country. Awareness of Cothran rose sixteenfold―from 1 to 16%.

And in 1999, an academic researcher duplicated the Calvin Coolidge experiment in Texas. Awareness of Coolidge also rose sixteenfold―from 1 to 16%.

Should the association wish to run the experiment again using the slogan "Bob James' Granddaughter Lucy is Awesome," I'm ready to grant my permission.