The discipline of scientific advertising was codified in 1923. Ninety-pages, no wasted words, and more durable business wisdom per page than most modern business books combined. The thesis: advertising is a measurable science. Everything that can be tested should be tested. Everything that can't should be suspicious.
Before scientific advertising became a discipline, advertising was art, big creative agencies, clever slogans, no accountability. The first generation of direct-response testers changed that with keyed coupons: little codes printed on each ad, so they could trace which newspaper, which city, which headline produced which number of orders. For the first time, an advertiser could say: "this ad produced 412 orders at a CPA of $2.18; this one produced 67 at $11.40." From there, you just run more of what works.
The one true rule. You don't know which of two headlines will win; run both and find out. You don't know whether coupon X or coupon Y pulls better; run both and find out. The act of testing is what separates practitioners from amateurs.
"Shoots sand 58 feet" vs. "shoots sand far." One is a demonstrable claim; the other is a brag. Prospects trust specific claims because specificity implies you actually know. Generalities imply you're making it up.
, on Pepsodent toothpaste: "Removes the film from your teeth." A specific mechanism, a specific benefit. The campaign built the brand that later became Colgate-Palmolive's Pepsodent.
Every ad should sell as hard as a trained salesperson would. A salesperson in a suit doesn't rely on charm; they ask questions, uncover pain, present benefits, handle objections, close with urgency. An ad should do the same. If your ad doesn't, a better salesperson wouldn't run it.
Don't assert; explain. If you say the product is the best, the reader's next thought is "says you." If you say why it's the best, the specific chemistry, the specific process, the specific difference, the reader evaluates the claim on its merits.
One of the most famous moves: Schlitz beer. Every brewery at the time steam-cleaned its bottles. It was industry-standard. Nobody had said it in advertising. The first writer to run the claim, in a campaign for Schlitz beer, wrote the campaign explaining the steam-cleaning process in detail. Schlitz went from #5 to #1.
The principle: whatever is true but unclaimed in your category, claim first. You don't have to do anything new, just say the thing everyone else takes for granted.
The early direct marketers used free samples and money-back guarantees aggressively. Let the product sell itself. Remove the risk of trial. He was doing this in the 1910s; modern SaaS "free trials" are the same idea.
A 10%-off sale is weaker than a specific, concrete offer. "Try it free for 30 days. If you don't see X, we refund you, and you keep the case." The shape of the offer matters more than the size of the discount.
An ad that tries to sell three things sells zero. An ad that tries to sell one thing to one person at one decision point sells. Multiple benefits are fine; multiple focus points aren't.
Is the closest thing marketing has to scripture, but not everything in the book is durable:
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