Weakness with consequence: Why marketing is like gravity


Marketing does like to believe in its own power. Persuasion, conversion, fans, advocates, loyalty. The language reveals the fundamental assumption that marketing is a strong force.

Yet when one looks at actual purchase data, there is little evidence that advertising works by converting or persuading.  The notion of creating passionate, committed and unwavering consumer devotion is nothing more than a marketing fiction.

As Professor Ehrenburg pointed out many years ago, if consumers had been strongly persuaded in the past, “there would be many near-100% loyal customers for each successful brand, and they would be important to its sales.”

But few people remain exclusively loyal to any one brand.  Brands are largely composed not of loyalists, but of light buyers who brand the brand  – as well as competing brands – occasionally. Which means there’s no such thing as ‘[insert brand] consumer.’ Just buyers of another brand who sometimes buy you.

These divided loyalties follow a predictable pattern. Brands share their customers with other brands, and do so more or less in line with market shares of those brands.  Buyers of any brand in a category are most likely to also buy the biggest brands in a given category. And they’re much less likely to also buy the smallest brands in the category.

Marketers might like to imagine the consumer in permanent orbit around their brand. But the fact of the matter is that people are happily polygamous in their brand ‘relationships’ for the simple reason that the choice between one brand and another is not that important.

The understanding that customers regularly buy from a repertoire of brands highlights the fact that advertising isn’t a ‘strong’ force that persuades and converts people.

It doesn’t have to.

Instead, advertising works as a weak force.

It works through nudging, not through bringing about Damascean experiences of conversion.

So in place of advertising operating as a ‘strong’ force that converts consumers, we should be thinking of it as ‘weak’ one, nudging people’s purchase behaviours, keeping our brand in their repertoires, or nudging it into people’s repertoires to add it as an extra or substitute brand.

Obviously all this doesn’t happen in blissful isolation. Competitor brands also exercise this nudging effect. And that means there will be a need for sustained and active brand maintenance.  People after all know that brands in any given category are broadly similar.

When so much of marketing is short-term in its horizons, understanding that the role of advertising is to keep nudging people, rather than convert them in a one-off act, reminds us that the real economic power of advertising is felt over the longer term. Advertising is not a one-off cost, as some would treat it. It’s a long-term investment in the health of a brand. For brands to survive and prosper, they require long-term commitment. They require long-term financial investment. And crucially, they require a sustained commitment to creative excellence.

While none of the above is at all new thinking (Ehrenberg was challenging the strong force theory of marketing decades ago), regarding advertising as weak force perhaps also serves to help us through some of the rhetoric that’s out there.

For we’ve been told by some that the alternative to ‘big idea’ marketing is ‘small idea’ marketing. That rather than the froth and the bluster of advertising that publicly seeks to arouse (allegedly) fervent devotion, we can deploy the humbler, and less public nudging effects of for example, behavioural economics. Or the harvesting of established consumer intent.

It’s a perspective that (perhaps unwittingly) is born of regarding advertising as a strong force.  But the perspective that advertising’s primary role is as a weak force erases the distinction between strong and weak effects. And between so-called ‘big’ and ‘small’ ideas.

Whether it’s shelf space, coupons, pricing, advertising, sampling, product design… what marketing does is nudge consumer behaviour.

Seen from this perspective, the question becomes – what along the consumer’s path to purchase can marketing do to nudge people’s behaviour?

consumer journey.013

In other words rather than indulge in some largely self-serving ideological battle between advertising and ‘other stuff’, we should be building effective ecosystems of weak effects.

Those whose egos cannot abide the notion that advertising and marketing more broadly work through exercising a weak rather than a strong influence might find some solace in considering the workings of gravity.

Gravity is the weakest force in nature – just jump into the air. With your few kilograms of muscle you’ve overcome  all 6 × 1024 kilograms of the Earth’s gravitational pull.

And yet this puny force is responsible for the Moon orbiting around the Earth, the Earth around the Sun, and the motion of the galaxies.

Weak does not mean without consequence.


  1. saltis99

    Gravity is indeed a weak force, but it is both constant and consistent and therefore effective. Maybe there is a lesson for media planners in there somewhere? But above all thanks for a (yet another) great piece!

    • Martin Weigel

      “Constant and consistent” – I love that. There’s probably a lesson in that for everybody involved. Starting with the setting and allocation of marketing budgets. Thank you!

  2. theescapepod

    the purchase decision reduces everyone to a blubbering mass of hearsay and internal bias. nudging works!

  3. BrainJuicer (@BrainJuicer)

    Great post (again!). I think the really important (and scary) word here is “ecosystems” of weak effects – working to understand how all the different nudges and triggers interact and align, which is probably the toughest part of researching and analysing all this stuff too.

  4. Emma Rogan

    This made me think of the JB Holt book about brands that become icons. Only a very few brands become iconic and experience the kind of impassioned loyalty that the rest only dream of. (And as you rightly argue here, even then they just get some of the sales). Holt argued that the actual brand expression (advertising, design) is just one small part of the equation, and that societal atmosphere, politics, outside cultural factors are the really powerful influencers. And in almost all cases, the iconic brand experiences a heyday that ultimately passes, as the planets of influence move out of alignment again…(and we advertisers/designers become rigidly fixed to the winning formula, assuming it was entirely within our control in the first place). Your most excellent P&G ‘For Moms’ is a case in point of maximizing on an outside event (The Olympics) to help tap into the mood in the room at a given moment. The authentic theme making the nudge all the more powerful.

    • Martin Weigel

      “Only a very few brands become iconic and experience the kind of impassioned loyalty that the rest only dream of.”
      No they don’t, I’m afraid.
      Brands get no more or less loyalty than one would expect, given their size.
      Impassioned loyalty is a marketing fiction.
      See the works of Ehrenberg, Scrive, Sharp, et al.

      • Emma Rogan

        Okay I will. Thank you….So are you saying that if we read about the success of an ‘iconic’ brand like Absolut (for example), it simply experienced sales relative to it’s size, and as investment increased, so did sales in proportion, helped by beautiful advertising nudges…And that at no point would it have had a higher ratio of repeat purchase (loyal consumers) than any other vodka brand at the time? And also – was it the beauty of the advertising work for Absolut that has led to it being an example of iconic brand success…ourselves congratulating ourselves for our good work, and making legend of the tale?

      • Martin Weigel

        I am saying that it – along with pretty much any other brand – has loyalty relative to its size.
        It is I am afraid, largely a fantasy that brands can enjoy extraordinary levels of loyalty.
        Big brands get slightly more loyalty than small brands. It’s what’s known as Double Jeopardy. But it is a small amount.
        The real difference between big and small brands is the number of buyers.
        And if you want to grow, increase the number of buyers.
        To be honest, I don’t know what people mean when they talk about ‘iconic’ brands. It’s just another piece of empty adland rhetoric.
        They probably just mean ‘big’.
        Or salient.
        (I’ve referenced and recycled the work of Ehrenberg et al plenty of this blog so have a rummage).

  5. Pingback: Escaping the tyranny of ‘advertising’ | canalside view
  6. Pingback: Si le marketing est une sommes de forces faibles, il ne doit pas se priver de se donner des directions | Notre Lien Quotidien