If you believe most marketing thought leaders, advertising works like a money printing machine. You show a clever ad, people fall in love with your brand, and sales skyrocket overnight. You put money in, you take more money out.
Except that is complete nonsense.
What Advertising Actually Does
In reality, advertising is far messier, more unpredictable, and less romantic than the ad industry likes to admit. It does not persuade people in a single moment. It does not turn strangers into loyal brand evangelists overnight.
Instead, it works in the background — nudging, reminding, and creating what researchers call mental availability. The idea that when people need what you sell, they might think of you first.
As Les Binet puts it: "Advertising increases and maintains sales by slightly increasing the chance that people will choose your brand — by making the brand easy to think of and easy to buy."
Slightly. That word matters. Advertising is a relatively weak force. It does not take people by the hand and walk them to the purchase. It does not create demand. It rarely makes anyone buy something they do not already want or need.
The Battery Brand Principle
I am not talking Beyoncé famous. I am talking Duracell famous. Standing out among thousands of other battery brands so that when you need new batteries and have to choose from six options at the checkout, you do not open a spreadsheet and compare them all. You just grab Duracell. That is what making a brand easy to think of actually looks like.
You did not buy your car because you saw an ad. You bought it because you needed or wanted a car. Then all those ads you had seen over the years, all those brand impressions, nudged you towards one brand over another. The ad did not create the purchase. It influenced the choice.
What Happens When You Stop Advertising
I always ask clients one question: "What do you think happens if you do not advertise your brand — if nobody sees any promotion from you at all?"
The answer: nothing. Nothing happens. If no one sees you, no one knows you exist. If no one knows you exist, no one will remember you when it is time to buy. You simply do not exist in your customer's mind.
Advertising does not create demand. It does not force purchases. But without it, brands fade from memory. The ones that stay visible, stay relevant. The ones that go dark, get replaced by whoever stayed in front of the audience.
The Practical Implication
If advertising works by creating mental availability, then the goal of your campaigns is not to convince people to buy right now. It is to be present and memorable across enough of your potential audience that when a need eventually arises — whether that is next week or next year — your brand is one of the options that comes to mind.
This is why consistent long-term advertising outperforms short campaign bursts. Each impression builds on the last. Fame compounds. And when the moment of purchase arrives, the brand that has been building mental availability over months and years has a structural advantage over the one that only shows up when they want to close a deal.
In Part 2, we look at the other half of the equation: physical availability — why being easy to buy matters just as much as being easy to think of.