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?
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.