Make Sure the People You Reach Can Actually Buy

What it is

Ten short chapters by the copywriter John E. Kennedy, published in 1905 by Judicious Advertising, the house magazine of Lord & Thomas, the Chicago agency he had joined the year before. His argument is that an ad has one job, and it’s the same job a salesman has:

“ADVERTISING is just Salesmanship-on-paper.” Chapter III, “The Responsive Chord in Advertising”

Anything less, in Kennedy’s terms, is “General Publicity,” which means keeping the name in front of people and hoping it helps. He had a line for that too: “When we multiply nothing by ten thousand we still have nothing as a result.”

What you’ll take from it

Start with Chapter II, “To Whom are You Advertising,” where Kennedy walks through the census income figures of his day and asks how many readers could actually afford a piano. Most of the people an advertiser pays to reach, it turns out, “cannot buy your Piano, no matter how much your advertising makes them want it.” So he concludes:

“What you need is not numbers of Readers, but Class of Readers.” Chapter II

Then in the last chapter he tells you how to prove it. Pick two cities of about the same size and run one kind of copy in each, with the same budget, for four months. Count the goods actually sold through the stores. Then swap the copy and run four more months:

“Now, cross the copy in each City for four months longer.” Chapter X, “How to Test Out General Advertising”

That’s a matched-market test, crossed over so the cities themselves can’t explain the result, and judged on the value of goods sold.

Where it shows up in your numbers

Reach tells you how many readers you paid for. What they’re worth depends on which readers they were. More than a century ago Kennedy was telling advertisers that the size of the audience is the wrong thing to buy, and that the only fair test is one that counts sales. Both still hold. Most dashboards still count the readers, so it’s worth checking what yours is counting.