Every now and then the topic of coverage, frequency and response rates arises and marketing or agency personnel find themselves trying to identify the optimal levels of communications spend required to maximise response ROI. Some argue that in order to maximise response rates the message has to be seen ’several times’ before it is acted upon. Others take the view that each ad has to stand on its own two feet and ‘do the the business’ each time it is seen. So what is the optimal frequency level required to maximise direct response ROI?

Over the last few weeks I’ve had cause to dip into both Drayton Bird’s excellent Common Sense Direct Marketing and also Graeme McCorkell’s equally robust and informative Direct and Database Marketing. Both the books emphasise what I know to be the case from countless experiments:

Any direct response ad must wash its face on the first exposure. Adding exposures actually decreases the overall response rate and consequently increases the overall cost per response.

McCorkell’s view is as follows: “each single press insertion or TV transmission is an event in its own right, required to justify its cost by a directly produced return”. Drayton Bird supports this view and even builds his argument with a case study from 1912. He quotes “a man called Shryer who studied what happens when you repeat advertisements. He learned that if you run an ad a second time, it does not get better results. It generally gets worse.”

Nearly 100 years after Shryer, this rule has also been found to apply online. Around 2000 I remember Doubleclick tracked the relationship between online ad exposures and online response rates. They found that with every layer of incremental frequency, response rates dropped by around 50%. This means that in an online environment you will get the highest % return from the first exposure i.e. by building coverage, not frequency. This was re-examined again by Atlas in 2004 and they reached similar conclusions about the importance of the first exposure. The extensive work of John Philip Jones at Syracuse University has also resulted in findings that support the importance of the first exposure. Jones found that:

1) One exposure has a significant effect on purchasing.
2) Two exposures do not have twice the effect of one exposure but usually cost twice as much.
3) This diminishing return deepens as more frequency is added to the campaign.

It’s interesting that “below the line” channels like direct mail and door to door often produce far higher response rates than “above the line” channels like TV, press and radio. Whilst the main reasons for this are related to the personal nature of direct mail and door to door, it is also worth bearing in mind that by definition these modes of communication are very low frequency channels; they basically optimise at 1 exposure. If below the line channels like direct mail were used at the same frequencies as above the line media i.e. 5-8 OTS then their response rates would be more than 90% lower those usually experienced.