The term exposure valuation refers to techniques used to determine the value to an advertiser of exposing a person to an advertising message.

Two general exposure valuation methods can be used in optimizing advertising campaigns:

1. Recency/Recall
2. Reach

Recency/Recall

The ability for a person to recall an advertising message depends on two ad timing related factors:

• How many times a viewer has already seen the ad, and
• When those previous exposures occurred.

Using recency/recall exposure valuation, the value of an initial exposure for a person to an ad is obviously different than the value of the 100th ad exposure. Similarly, the value of several exposures to the same ad clustered during a single program is different than the same number of exposures distributed over a longer period of time.

Recency/recall exposure valuation exposure valuation is a systematic method of assigning value to advertising exposure based on a person's ability to recall an advertising message. For a particular ad, the value of each exposure for each member of the sample audience could be different depending on the spacing of all previous exposures of each sample member to the ad.

Recency/Recall - Distributed Exposure

The figure above illustrates the recall pattern for a person that might result from being exposed to a sequence of six ads in an ad campaign over a period of several weeks.

As the plot suggests, the ability for a person to recall elements in the ad declines over time and requires periodic refreshing.

Recency/Recall - Clustered Exposure

In comparing the distributed exposure plot with the clustered exposure plot above, we can see that distributed exposure spacing is better than clustered exposures in maintaining message recall. This plot shows a person exposed to six ads over the same period of time. In this case, however, the ads are clustered near the beginning of the campaign. Initially there is impressive influence levels, but, without refreshing, this will drop consistently over time. An ad has the greatest influence when exposure occurs with high recency.

Reach

Exposure valuation based on reach makes the somewhat unrealistic assumption that if a person is exposed at some level (often three exposures during a four week period), then the person has been effectively exposed. For the same exposure patterns described above, the corresponding reach plot is shown below.

Reach Exposure

In this case, because the person has been exposed at a level greater than the required three times, the assumed level of reach influence for the entire duration of the advertising campaign is, by definition, 1.00.

It is clear that, in some situations, optimization based on recency/recall should yield more efficient and optimal results than optimization based on reach or effective reach.