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2 lessons from the rule of three

2 lessons from the rule of three

Marketing academics may be disputing the TV buyer’s rule of three concept, but they have much to learn from each other.

As a young man, my father-in-law did his military service in a naval battery protecting Helsinki harbour. It was an experience that gave him an enduring respect for discipline, persistent tinnitus and a lot of now-redundant knowledge of ballistics.  

One thing he learned was that, when engaging the enemy, a naval battery always fires three shots: one where you think the target is, one a bit far, one a bit short.

Back then, bombardiers were fairly confident they knew where their targets were, but not 100% sure, so they would send three shots in the hope that one would hit. 

Old-fashioned TV buyers also used a rule of three: TV campaigns are most effective when you aim for your audience to see the ad three times. Any fewer and they might not remember it; any more and they’ll not remember it more.

This advertising heuristic even echoes a military mnemonic: good communication requires that you “tell ’em what you’re gonna tell ’em, tell ’em and then tell ’em what you told ’em”.

No-one really knows where this media folk tradition comes from. The great Erik du Plessis tried, and failed, to find the source of the story in The Advertised Mind (2004) — still the best book on advertising published this millennium.

But it fits well with most theories of memory. Repeat after me: repetition is required for effective encoding. 

Challenging folk wisdom

The rule of three is, however, now being challenged by modern marketing science. It is the job of clever academics to challenge folk wisdom, often with the express intention of exposing how stupid the folk are.

And so marketing scientists are debunking the value of frequency and preaching the primacy of reach. Rather than wasting our money repeating ourselves to the same audiences at 3+ cover, we should maximise 1+ cover, reaching as many people as we can with the budget available. 

The theory is that, given most people in most markets are only ever light buyers of a category, we should cast our net wide and get many people to buy once, rather than try to talk to a specific audience frequently and turn them into loyalists. 

This theory of reach doesn’t just apply to TV. Some interesting research from Rikard Wiberg at Swedish marketing consultancy Pace has shown that even on Facebook and Instagram, using reach strategies can deliver more incremental value than optimising for conversions, which may result in targeting ads at people who were going to buy anyway. 

This may well be true, but that doesn’t necessarily mean that the rule of three rule of thumb is false. And this is where my Finnish father-in-law might have much to teach us. 

Opportunity to see

Companies like Lumen and TVision have made it their business to demonstrate that there is a big difference between the opportunity to see something and actually seeing it.

Just because something is viewable doesn’t mean that it will be viewed — still less remembered or acted on. 

The latest data from TVision’s panels in the US and the UK suggests that only around 35% of TV ads actually get looked at. The rest play out to empty rooms or people looking away from the screen. These impressions may still have value, but only deliver the A out of the full AV experience.

When you take this into account, you begin to have more respect for the folk traditions of media planners. Maybe 1+ coverage is most effective. But if only one in three TV ads get attended to, you need to buy 3+ coverage to be sure of delivering a 1+ result.

It looks like the old wise men of media had found a practical way of acting on the latest theory, avant la lettre.

Grace Kite noted when discussing Wiberg’s results that sometimes buying coverage on Facebook will end up increasing frequency anyway. It’s interesting to note that for other media, the inverse may also be true: frequency may be required to achieve coverage. 

What about engagement?

Merely reaching people is, however, not even half the story. How long you engage them for is also vitally important.

Du Plessis’ book cites detailed evidence on the close correlation between time of exposure and strength of memory encoding. He uses this to explain why 60-second ads are much more effective than 30-second ads — if you can hold people’s attention. The quantity of the impressions should not be divorced from their quality.

Debates between the theoretical models of marketing scientists and the practical nous of business professionals suggest that each has much to learn from the other.

The academics have the perspective and conceptual tools to enlighten practitioners. But the lived experience of planning and buying campaigns — and reporting on their success to demanding clients — may give practitioners an intuition about the reality of advertising attention that the theorists lack.

Experience without theory is blind; but theory without experience is dumb.

The point of the debate must be to learn — and help others learn. And my father-in-law may have a second lesson to impart. His rule of three wasn’t just about projecting ordnance; it was also about receiving information.

The 3+ artillery coverage meant that every salvo was a test-and-learn experiment. The observers would report not only if a shell had hit the target, but which shell had hit. Changes to range and targeting would be made accordingly.

Advertising is rarely a one-shot engagement. There is always another “burst” of activity; there’s always the next “campaign”. If we treat each investment as a chance to go round the OODA loop, then we might achieve our objectives and live to fight another day. 

Michael Follett is managing director at Lumen Research and one of the media industry’s leading experts on attention measurement and effectiveness. He writes for The Media Leader each month.

Bob Wootton, Principal, Deconstruction , on 01 Feb 2024
“Great piece, Michael, enough content to persuade with a lightness of touch that helps it get through!”

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