Reach vs Frequency - What Vaccines and Advertising have in common
There’s nothing like a mortal threat to focus our minds on science. Certainly, most of us know more about vaccines than we did a year ago. For instance, most of us will have seen research data that contrasts the level of protection offered by one Covid jab versus two.
The numbers vary according to the vaccine, study, and age of the recipient, but typically we hear that a single jab gives moderate protection - say, 60% - while a second jab ramps that figure up to around 95%.
At this point, media minds might find themselves seeing a comparison with the old ‘reach versus frequency’ debate: Is it better to reach more people less often, or fewer people more often?
Ideally, you’d want the best of both worlds. But as our vaccine roll-out shows - and any media planner can corroborate - resources are limited and time is of the essence. So, quite often, you’ve got to pick one or the other.
If immunity after one jab is 60%, then no matter how many people you inject - this is the reach part - their immunity is still only 60%. To increase immunity, you need to inject the same people a second time. This is where frequency makes the difference. Current government policy is largely reach-based. It wants to get as many people as possible injected once.
In the world of media, we make this calculation all the time. If a campaign that delivers one exposure to a given number of people is providing a certain level of brand lift - say, 3% - and you want to extend the campaign, how you do so will affect the brand lift you can expect to see.
If you aim to reach a greater number of new people, you can expect to see the total brand lift stay the same, at 3% - just among a wider group of people. But if you reach the original single-exposure group for a second time, you can expect to see the brand lift in that cohort rise; let’s say to 6%. Increasing the frequency concentrates the brand lift; just as increasing vaccine frequency enhances the level of protection among those vaccinated.
The basic principle of balancing reach and frequency is as old as advertising itself, and plenty of alternative analogies exist, such as the slightly leading one that asks rhetorically whether you should plant fewer seeds and water them regularly (frequency overreach, and a sensible recipe for a nice yield) or plant more seeds and only water them once (reach over frequency, also known as a parched, failed crop).
The difference in the argument these days is the fact that brand lift has become efficiently measurable in a way that it never was before. Using a simple and inexpensive piece of software installed on publishers’ sites, we can audit the effect digital campaigns have on advertisers’ key brand metrics: brand awareness, brand consideration, brand preference, and action intent.
This allows us to consider the impact of factors including creativity, messaging, the context in which it is exposed to the audience, the receptiveness of that audience - as well as macro factors and competing messages from other brands.
The availability of this data drives greater effectiveness because it helps balance the need for both quality and quantity. Quality is pointless without quantity and quantity is pointless without quality. Showing a poor campaign to many is just wasting money. Likewise, creating the best campaign in the world and showing it to a handful will have little effect on business objectives.
However, by capturing effectiveness data at scale, we can more efficiently determine if our campaigns - or indeed our vaccine programmes - are working, and make better, more informed decisions around their subsequent roll-out.
Brand Metrics https://www.brandmetrics.com/#home