Complete citation: Clinton Amos Rosemary, Gary
Holmes & David Strutton. (2008). Exploring the
relationship between celebrity endorser effects and advertising effectiveness, A
quantitative synthesis of effect size, International Journal of Advertising,
27(2), pp. 209–234.
Purpose of reading: The point of
our study is to provide a quantitative summary of the relationship between
celebrity endorser source effects and effectiveness in advertising.
Q1:
What are the most important source effects of celebrity endorsement?
Q2:
What effect does the celebrity endorser/product fit have on celebrity
endorsement effectiveness?
Q3:
Within the relevant research domain, what methodological variables produced the
most variation in terms of significant findings?
Q4:
How do interaction effects differ from main effects in celebrity endorsement
source effects literature and what implications do these differences have for
researchers?
Q5:
What potentially rewarding topic areas remain relatively under-explored in the
current celebrity endorser literature?
Theoretical
foundation:
The source
credibility model
– collected of
celebrity trustworthiness, celebrity expertise, and celebrity attractiveness
– capture each
of the three celebrity source effects identified as most influential in this
research.
– As a basis for
evaluating consumer perceptions of a celebrity endorser.
The source
attractiveness model
– Celebrity familiarity
and likeability were also revealed as highly influential source effects.
Familiarity and likeability might each make a substantial additive contribution
to the predictive ability of the source credibility model when it is used in a celebrity
endorsement context.
Methodology: Among the original 266 total effects,
185 were statistically significant (p < 0.05). Forty-four per cent of
the retained studies examined celebrity/product fit. With respect to methods
characteristics, 86% of studies sampled reported main effects, 62% used a
survey instrument, and 52% used a student sample. Exactly 60% of the studies
used a US-based sample.
Ø Meta-analysis
overview
Ø Effect
size
Ø Selecting
the relevant literature
Eighty-seven
studies were originally identified as worthy of further evaluation. Of this
sample, 12 articles were conceptual and another 43 studies failed to report
information required to conduct the analysis due to their focus on aspects of
celebrity endorsers outside the realm of source effects. In total, then, 32
studies were retained for analysis in this Meta analysis. Total effect size was
266. In all, 27 journal articles, two unpublished studies, and three
unpublished dissertations were included.
Results and conclusions: The results of
our study clearly support the efficiency of celebrity endorsements is subject
to reduction by advertising clutter, selective attention, and the time available to
identify and evaluate the advertisement. As a result, trial results should be interpreted with concern.
Next, celebrity endorsers may have a greater influence on college students than
on members of more cross-sectional samples. This suggests students may represent an ideal
target market for advertisements that use celebrity endorsers. Finally,
celebrity endorsers were far less significant in non-US studies. This suggests
non-US populations are less responsive to celebrity endorsers. However, the
persistent use of celebrity endorsers in non-US countries by practitioners
suggests that many non-US markets may exist where celebrity endorsement is
likely to prove an effective advertising strategy.
Future research ideas: extension might
entail exploring whether celebrity endorsers perceived as responsible
contribute to customer retention and repurchase intentions and research is
surely needed on celebrities who portray the ‘bad boy’ or ‘bad girl’ image and
their effectiveness as celebrity endorsers. These sorts of anti-celebrities may
convey a certain image of danger, risk, or toughness that may appeal
to some consumers or alienate others. The viewpoint of any outcome
should be more in detail examined.
