Deciding on Reach, Frequency, and Impact

Media selection is finding the most cost-effective media to deliver the desired number and type of
exposures to the target audience.What do we mean by the desired number of exposures? The advertiser
seeks a specified advertising objective and response from the target audience—for example,
a target level of product trial. This level depends on, among other things, level of brand awareness.
Suppose the rate of product trial increases at a diminishing rate with the level of audience awareness,
as shown in Figure 18.2(a). If the advertiser seeks a product trial rate of T *, it will be
necessary to achieve a brand awareness level of A*.
The next task is to find out how many exposures, E *, will produce a level of audience awareness
of A*. The effect of exposures on audience awareness depends on the exposures’ reach, frequency,
and impact:
• Reach (R). The number of different persons or households exposed to a particular media
schedule at least once during a specified time period
• Frequency (F). The number of times within the specified time period that an average person
or household is exposed to the message
• Impact (I). The qualitative value of an exposure through a given medium (thus a food ad will
have a higher impact in Bon Appetit than in Fortune magazine)
Figure 18.2(b) shows the relationship between audience awareness and reach. Audience awareness
will be greater, the higher the exposures’ reach, frequency, and impact. There are important trade-offs
here. Suppose the planner has an advertising budget of $1,000,000 and the cost per thousand exposures
of average quality is $5. This means 200,000,000 exposures ($1,000,000 ÷ [$5/1,000]). If the advertiser
seeks an average exposure frequency of 10, it can reach 20,000,000 people (200,000,000 ÷ 10) with the
given budget. But if the advertiser wants higher-quality media costing $10 per thousand exposures, it
will be able to reach only 10,000,000 people unless it is willing to lower the desired exposure frequency.
The relationship between reach, frequency, and impact is captured in the following concepts:
• Total number of exposures (E). This is the reach times the average frequency; that is, E = R × F,
also called the gross rating points (GRP). If a given media schedule reaches 80 percent of homes
with an average exposure frequency of 3, the media schedule has a GRP of 240 (80 × 3). If another
media schedule has a GRP of 300, it has more weight, but we cannot tell how this weight
breaks down into reach and frequency.
• Weighted number of exposures (WE). This is the reach times average frequency times average
impact, that is WE = R × F × I.
Reach is most important when launching new products, flanker brands, extensions of wellknown
brands, or infrequently purchased brands; or when going after an undefined target market.
Frequency is most important where there are strong competitors, a complex story to tell, high consumer
resistance, or a frequent-purchase cycle.25
A key reason for repetition is forgetting. The higher the forgetting rate associated with a brand,
product category, or message, the higher the warranted level of repetition. However, advertisers
should not coast on a tired ad but insist on fresh executions by their ad agency.26 GEICO has found
advertising success by keeping both its campaigns and their executions fresh.