pact. The media planner recognizes important trade-offs among reach, frequency, and
impact. Suppose the planner has an advertising budget of $1,000,000 and the cost per
thousand exposures of average quality is $5. This means the advertiser can buy
200,000,000 exposures ($1,000,000[$5/1,000]). If the advertiser seeks an average
exposure frequency of 10, then the advertiser can reach 20,000,000 people
(200,000,00010) 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 follow-
ing concepts:
■ Total number of exposures (E):This is the reach times the average frequency; that
is,ERF. This measure is referred to as the gross rating points(GRP). If a given
media schedule reaches 80 percent of the homes with an average exposure fre-
quency of 3, the media schedule is said to have a GRP of 240 (803). If an-
other media schedule has a GRP of 300, it is said to have 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 WERFI.
The media planner has to figure out, with a given budget, the most cost-effective
combination of reach, frequency, and impact. Reach is most important when launch-
ing new products, flanker brands, extensions of well-known brands, or infrequently
purchased brands, or going after an undefined target market. Frequency is most im-
portant where there are strong competitors, a complex story to tell, high consumer
resistance, or a frequent-purchase cycle.^24
Many advertisers believe a target audience needs a large number of exposures for
the advertising to work. Too few repetitions can be a waste, because they will hardly
be noticed. Others doubt the value of high ad frequency. They believe that after peo-
ple see the same ad a few times, they either act on it, get irritated by it, or stop notic-
ing it. Krugman asserted that three exposures to an advertisement might be enough:
The first exposure is by definition unique. As with the initial exposure to anything,
a “What is it?” type of cognitive response dominates the reaction. The second expo-
sure to a stimulus... produces several effects. One may be the cognitive reaction that
characterized the first exposure, if the audience missed much of the message the first
time around.... More often, an evaluative “What of it?” response replaces the “What
is it?” response.... The third exposure constitutes a reminder, if a decision to buy
based on the evaluations has not been acted on. The third exposure is also the be-
ginning of disengagement and withdrawal of attention from a completed episode.^25Krugman’s thesis favoring three exposures has to be qualified. He means three ac-
tual impressions or advertising exposures—the person sees the ad three times. These ex-
posures should not be confused with vehicle exposures. If only half the magazine readers
look at magazine ads, or if the readers look at ads only every other issue, then the ad-
vertising exposure is only half of the vehicle exposures. Most research services esti-
mate vehicle exposures, not ad exposures. A media strategist would have to buy more
vehicle exposures than three to achieve Krugman’s three “hits.”^26 Another factor ar-
guing for repetition is that of forgetting. The job of repetition is partly to put the mes-
sage back into memory. The higher the forgetting rate associated with a brand, product
category, or message, the higher the warranted level of repetition. But repetition is
not enough. Ads wear out and viewers tune out. Advertisers should not coast on a
tired ad but insist on fresh executions by their advertising agency. For example, Du-
racell can choose from more than 40 different versions of its basic ad.
CHOOSING AMONG MAJOR MEDIA TYPES
The media planner has to know the capacity of the major media types to deliver reach,
frequency, and impact. The major advertising media along with their costs, advan-
tages, and limitations are profiled in Table 5.7.^587