ORIGINAL EMPIRICAL RESEARCH
The effectiveness of celebrity endorsements: a meta-analysis
Johannes Knoll
1
& Jörg Matthes
1
Received: 18 February 2016 /Accepted: 25 September 2016 / Published online: 12 October 2016
#
The Author(s) 2016. This article is published with open access at Springerlink.com
Abstract Celebrities freque ntly endorse products, brands,
political candidates, or health campaigns. We investigated
the effectiven ess of suc h endorsements by meta-analyzing
46 studies published until April 2016 involving 10,357 partic-
ipants. Applying multilevel meta-analysis, we analyzed celeb-
rity endorsements in the context of for-profit and non-profit
marketing. Findings revealed strong positive and negative ef-
fects when theoretically relevant moderators were included in
the analysis. The most positive attitudinal effect appeared for
male actors who match well with an implicitly endorsed object
(d = .90). The most negative effect was found for female
models not matching well with an explicitly endorsed object
(d = −.96). Furthermore, celebrity endorsements performed
worse compared to endorsements of quality seals, awards, or
endorser brands. No publication bias was detected. The study
has theoretical and practical implications, and provides an
agenda for future research.
Keywords Meta-analysis
.
Celebrity endorsements
.
Advertising effects
Celebrity endorsements are a well-established marketing strat-
egy used since the late nineteenth century (Erdogan 1999).
While the strategy was first applied in traditional brand or
product marketing (Erdogan 1999), it has spread to any form
of marketing communication, including political marketing
(Chou 2014, 2015), health communication, and the marketing
of non-government organizations (NGOs; *Jackson 2008;
*Wheeler 2009; *Young and Miller 2015). Current estimates
indicate every fourth to fifth advertisement incorporates this
strategy, though this varies across countries (USA: 19–25%,
Elberse and Verleun 2012; Stephens and Rice 1998;UK:
21%, Pringle and Binet 2005;India:24%,Crutchfield2010;
Japan: 70%, Kilburn 1998; Taiwan: 45%, Crutchfield 2010).
In addition, longitudinal analyses show a steady increase over
the past years (Erdogan 1999; Pringle and Binet 2005).
Hence, many studies have been conducted to test whether
consumer attitudes and behavior are changed by celebrity en-
dorsements. So far, results have been summarized in three
narrative (Bergkvist and Zhou 2016; Erdogan 1999;Kaikati
1987) and one quantitative review (Amos et al. 2008; see the
Appendix for a summary of the review). The quantitative re-
view of Amos and colleagues focused on source effects of
celebrity endorsers. In short, it asked which source variables
(e.g., expertise, attractiveness) exert which influence on ad-
vertising effectiveness. However, it did not test whether the
obtained effect sizes were significant, but solely tested wheth-
er they were significantly different from each other. Hence, up
until now, there is no meta-analytic knowledge about whether
celebrity endorsements actually influence consumers’ re-
sponses, including the size of their influence. In addition, there
is no knowledge about whether effects differ in terms of spe-
cific outcomes (e.g., cognitive, affective, behavioral). The rea-
sonisthatAmosetal.(2008) applied only a combined mea-
sure of advertising effectiveness. Fu rthe rmore, frequently
claimed propositions like the match-up hypothesis or the
proposition of stronger effects in the case of unfamiliar brands
have never been tested on a meta-analytic level. This seems
particularly pressing considering the fact that practitioners fre-
quently refer to such claims (Erdogan 1999). Besides, there
* Jörg Matthes
joerg.matthes@univie.ac.at
Johannes Knoll
johannes.knoll@univie.ac.at
1
Department of Communication, University of Vienna, Währinger
Straße 29, A-1090 Vienna, Austria
J. of the Acad. Mark. Sci. (2017) 45:55–75
DOI 10.1007/s11747-016-0503-8
are conflicting results of individual studies, for instance, when
it comes to the endo rser’s sex or endorsement repetition
(Bergkvist and Zhou 2016;Erdogan1999). Last but not least,
numerous studies have been conducted since the last quanti-
tative review in 2004 (Bergkvist and Zhou 2016).
The present meta-analysis seeks to address these shortcom-
ings by integrating research published through April 2016, by
reporting average effect sizes according to various advertising
outcomes including respective confidence intervals, and by
performing moderator analyses testing the impact of various
endorser and endorsed object variables. In terms of methodo-
logical advancement, we apply multilevel modeling account-
ing for the dependence of multiple effect sizes and we estimate
publication bias, both important issues in meta-analysis
(Borenstein et al. 2009). Finally, we provide practitioners with
empirically derived implications for how to choose the right
celebrity and offer researchers an agenda for future research.
Conceptual framework
Following McCracken (1989), celebrity endorsements are un-
derstood as a marketing technique in which an individual
enjoying public recognition Buses this recognition on behalf
of a consumer good by appearing with it in an advertisement^
(p. 310). The effects of endorsements can well be explained
within the advertising effectiveness model provided by
Ladvidge and Steiner (Lavidge and Steiner 1961). Studies
have mostly investigated celebrity endorsements according
to one or more of the model’s advertising functions
(Bergkvist and Zhou 2016; Erdogan 1999; Kaikati 1987).
Furthermore, the model has revealed itself as fruitful in a
similar meta-analysis (Grewal et al. 1997). It enables a
systematic organization of the analyzed dependent variables
and moderators, and specifies their relationships (see Fig. 1).
According to the model, advertising serves to influence three
basic psychological dimensions: the cognitive, the affective,
and the conative. BAdvertising’s cognitive function provides
information and facts for the purpose of making consumers
aware and knowledgeable about the sponsored brand.
Advertising’s affective function creates liking and preference
for the sponsored brand – preference presumably refers to
more favo rable att itudes. Advertising’s affective function,
therefore, is to persuade. Finally, advertising’s conative func-
tion is to stimulate desire and cause consumers to buy the
sponsored brand^ (Grewal et al. 1997, p. 2). Important to note,
we do not suggest that these outcomes necessarily take place
in a particular sequence (i.e., cognition = > affect = > behavior).
Following more recent advancements in the conceptualization
of advertising effects, we propose that each of the outcomes
may be independently influenced by celebrity endorsements.
In addition, all outcomes are assumed to be interrelated. They
possibly influence or interact with each other (Vakratsas and
Ambler 1999). This is indicated by the double-headed arrows
in Fig. 1.
Cognitive effects
Cognitive effects include awareness and knowledge about an
endorsed object. Establishing awareness starts from creating
attention and interest (Lavidge and Steiner 1961). Directing
one’s attention involves controlled as well as automatic pro-
cesses (Kahneman 1973). Both processes can be influenced
by celebrity endorsements. First, people who are interested in
a particular celebrity are assumed to purposefully direct their
Note. = path tested = path not tested
Celebrity Endorsement
versus No or Non-
Celebrity Endorsement
Attention and Interest
Awareness
Estimations
Perceptions
COGNITIVE
Attitude toward Ad
Attitude toward Object
AFFECTIVE
Behavioral Intentions
Behavior
CONATIVE
Endorser Sex, Type, and Match
Endorsement Explicitness and Frequency
Familiarity of Endorsed Object
Endorsement Type of Comparison Group
MODERATORS
Fig. 1 Celebrity endorsement effectiveness model adapted from Grewal et al. (1997)
56 J. of the Acad. Mark. Sci. (2017) 45:55–75
attention to this celebrity’s ad (*Wei and Lu 2013). Second,
people’s attention is automatically directed. Humans tend to
give preferential treatment to stimuli that are related to their
goals (Lang 2000). In addition, celebrities are well-known,
resulting in more accessible representations in memory
(Erfgen et al. 2015). This should foster automatic attention,
too (Bargh and Pratto 1986).
Once a celebrity endorsement grabs their attention, consumers
are assumed to become more interested in the advertised object
as compared with a non-endorsed or other-endorsed object. This
due to the fact that celebrities possess inherent news value caused
by their celebrity status (Corbett and Mori 1999). Since celebri-
ties are generally liked, consumers also tend to be more motivat-
ed to assess what kind of object a celebrity is endorsing. As a
result, object recall and recognition is assumed to be enhanced
due to greate r message elaboration (*Petty et al. 1983).
In terms of knowledge, celebrity endorsements are as-
sumed to influence the meaning of the endorsed object
(*Miller and Allen 2012) as well as perceptions about its
price, its taste level, the risk of buying it, or the perceived
information value of the endorsement (*Biswas et al. 2006;
*Dean and Biswas 2001;*Freiden1982; *Friedman et al.
1976; *Young and Miller 2015). Based on the mechanism
behind these effects, consumers are assumed to conclude
that an object has a specific attribute when they perceive
this object as paired with a celebrity known for this attribute
(e.g., premium price with a high-class celebrity; *Miller
and Allen 2012). The process can be conceptualized as
propositional learning (De Houwer 2009). Consumers have
experienced in their past that people freq uently pres ent
themselves with objects they share similarities with (Elliot
and Wattanasuwan 1998). BOnce a relation between two
events has been discovered in the past, it is likely that this
knowledge is used to generate propositions about similar
events in the present^ (De H ouwer 2009,p.8).Asaresult,
celebrity attributes created through celebrities’ role in soci-
ety transfer to associated objects (McCracken 1989). In
conclusion, it is proposed that celebrity endorsements in-
fluence consumers’ cognitions including attention and in-
terest, awareness, a s well as perceptions.
H1: As compared with non-celebrity endorsements or no
endorsements, celebrity endorsements evoke greater
attention, interest, and awareness as well as percep-
tions more in line with the respective endorser.
Affective effects
Affective effects pertain to attitudes toward the ad and atti-
tudes toward the advertised object. This influence may best be
explained with regard to balance theory (Heider 1946, 1958;
see also Mowen and Brown 1981). The theory explains a
person’s desire to maintain consistency among a triad of
linked cognitions. It follows that people generally strive for
a consistent organization of their cognitive structures,
experiencing this state as most tension-free. In the case of
celebrity endorsements, the cognitive triad consists of the con-
sumer, the celebrity, and the endorsed object or the endorsed
ad, respectively. A consistent state is achieved if the consumer
perceives the celebrity and the endorsed object/ad as equally
valenced (i.e., as both positive or both negative) because ce-
lebrities endorsing an object are usually seen as positively
related to that object or the respective ad (Erdogan 1999).
Starting from the premise that researchers and practitioners
usually employ likeable celebrities, it can be hypothesized that
celebrity endorsements positively impact consumers’ attitudes
toward the ad and attitudes toward the endorsed object. Only
then are consumers’ attitudes and their liking for the respec-
tive celebrity of the same valence (i.e., both positive; Heider
1946, 1958). Although there may be similar effects for like-
able non-celebrity endorsers, these are assumed to be notably
weaker. This is due to the fact that consumers are familiar with
celebrities by definition. As a result, relationships with celeb-
rities are more affectional as compared with unknown non-
celebrity endorsers (Dibble et al. 2016).
H2: As compared with non-celebrity endorsements or no
endorsements, celebrity endorsements evoke more
positive attitudes toward the ad and the endorsed
object.
Behavioral effects
Behavioral effects include purchasing or using an object (e.g.,
*Freiden 1982; *Kamins 1989; *Kamins and Gupta 1994;
*Roozen and Claeys 2010; *Siemens et al. 2008), sharing
object information, volunteering, supporting a charitable
cause, or voting for a political candidate (Myrick and Evans
2014; *Pease and Brewer 2008;*WeiandLu2013;*Wheeler
2009). Such effects are frequently explained with regard to the
theory of planned behavior (Ajzen 1991). According to the
theory, behavior is strongly determined by behavioral inten-
tions. These are, in turn, influenced by consumers’ attitudes,
the perceived subjective norm, and the perceived behavioral
control. As long as consumers are able to exert the respective
behavior (behavioral control), and as long as consumers do
notfeelsocialpressuretoavoid the behavior (subjective
norm), attitudes largely predict behavioral intentions. The as-
sumptions have been supported by various meta-analyses
(Armitage and Conner 20 01; Kim and Hunter 1993).
Accordingly, the more positive attitudes assumed in H2
should lead to stronger behavioral intentions and respective
J. of the Acad. Mark. Sci. (2017) 45:55–75 57
behavior. Corresponding effects were, for instance, found by
Fleck et al. (2012) and Mishra and Mishra (2014). We conse-
quently hypothesize:
H3: As compared with non-celebrity endorsements or no
endorsements, celebrity endorsements evoke stron-
ger behavioral intentions and behavior.
Moderators
Studies investigating the applie d advertising effectiveness
framework have consistently found that people respond dif-
ferently to advertisements depending on characteristics of the
ad, the advertised object, and individual characteristics
(Vakratsas and Ambler 1999). This is frequently intended by
the advertiser, tailoring advertisements to specific consumers
and their needs (Lavidge and Steiner 1961). In line with this
reasoning, we included various moderators within our frame-
work accounting for the fact that consumers do not respond
uniformly to advertising (cf. Figure 1;LavidgeandSteiner
1961). Following Grewal et al. (1997), our analysis of mod-
erators is limited to those that (1) are theoretically relevant, (2)
provide a sufficient number of effect sizes, (3) show sufficient
variance to test the moderation, and (4) are important to ad-
vertisers. In te rms of number of effect s izes, Higgins and
Green (2011) suggest considering moderator analysis only if
there are ten or more studies incorporating the moderators.
Seven moderators met the criteria: endorser sex, endorse r
type, endorser match, endorsement explicitness, endorsement
frequency, familiarity of the endorsed object, and endorsement
type of the comparison group.
Endorser sex Though endorser sex has generally been
viewed as inf luential (e.g., Er dogan 1999; McCracken
1989), hardly any study explicitly addressed this variable in
empirical research. Most studies have investigated either fe-
male or male endorsers (for the only exception, see Freiden
1984). BThe dearth of research on endorser gender effects is
somewhat surprising as persuasion research shows that men
and women respond differently to male and female
communicators^ (Bergkvist and Zhou 2016, p. 11). Hence,
meta-analysis seems especially valuable (Lipsey and Wilson
2001). Assumptions about possible effects may be derived
from studies on non-celebrity spokespersons. According to
Kenton (1989), the credibility and persuasiveness of a spokes-
person depends on four dimensions: goodwill and fairness
(e.g., unselfishness), prestige (e.g., power, status), expertise
(e.g., competence), and self-presentation (e.g., confidence).
Research has revealed women to be higher ranking on good-
will and fairness, whereas men outperform women on the
remaining dimensions (Kenton 1989). As a result, male
spokespersons were frequently more persuasive than female
ones (e.g., Cabalero et al. 1989;Whittaker1965). Transferring
this to the present context, consumers may perceive male ce-
lebrity endorsers as more credible due to higher levels of ex-
pertise and prestige (Cabalero et al. 1989). As a result, male
celebrities are assumed to evoke stronger endorsements ef-
fects when compared to female ones.
H4: Male celebrity endorsers evoke stronger endorse-
ment effects when compared to female ones.
Endorser type No study has explicitly investigated different
types of celebrity endorsers. Instead, studies have typically
focused on only one type. For instance, studies have explored
actors, models, musicians, athletes, or TV hosts (e.g., *Dean
and Biswas 2001;*Frizzell2011;*PeaseandBrewer2008;
*Wheeler 2009;*WeiandLu2013). By joining the results of
several studies, meta-analysis can provide information wheth-
er certain endorser types perform better than others do (Lipsey
and Wilson 2001).
Starting from the premise that endorsement effects de-
pend on the strength of the relationship a consumer shares
with a celebrity (McCracken 1989), research on parasocial
interaction can provide insights. Specifically, studies have
revealed that people tend to develop relationships with ce-
lebrities, merely known from the media, just as they would
do with real life persons (Dibble et al. 2016):
Upon en-
countering a celebrity on television, radio, or the Internet,
consumers may parasocially interact with the celebrity,
storing this experience in a relationship schema (Klimmt
et al. 2006). The m ore frequently a celebrity is encountered
and the more intense each interaction experience is, the
more likely a strong consumer –celebrity relationship is
formed (Klimmt et al. 2006). Looking at different kinds
of celebrities, consumers are particularly likely to form a
strong relationship with actors. First, consumers are
audiovisually exposed to actors, creating a particularly rich
experience, and second, experience is usually based upon
multiple encounters over a longer period: BOver time,
viewers become famil iar with char acters and pe rformers
on continuing series and often feel as though they know
these individuals as well as they know their friends and
neighbors. The importance of characters t o viewers fre-
quently extends beyond the viewing situation to include
the sense of having personal relationships with the charac-
ters, deep concern about what happens in their ‘lives,’ and/
or a desire to become like them in significant ways^
(Hoffner and Buchanan 2005, p. 326).
According to McCracken (1989), this exact type of rela-
tionship causes consumers to accept celebrities’ influence
more readily. The following hypothesis is proposed:
58 J. of the Acad. Mark. Sci. (2017) 45:55–75
H5: Actors elicit stronger celebrity endorsement effects
when compared to other types of celebrities such as
models, musicians, athletes, or TV hosts.
Endorser match Several studies have investigated the so-
called product match-up hypothesis that assumes the effec-
tiveness of celebrity endorsements is partially dependent
on the degree of perceived fit between an endorsed object
and the respective celebrity (Erdogan 1999). A good match
may be an attractive model presenting cosmetics, whereas
a bad match may be an athlete trying to sell a guitar. The
process underlying the product m atch-up hypothesis can be
explainedwithregardtoSocialAdaptationTheory(Kahle
and Homer 1985;Kamins1990)orSchemaTheory(Lynch
and Schuler 1994). Social Adaptation Theory assumes that
people use information sources as long as they facilitate
adaptation to their environment. If a match exists between
a spokesperson and a product on some relevant attribute,
the spokesperson becomes an information source of adap-
tive significance on which people may rely (Kamins 1990).
Schema Theory posits that attributes of celebrities can be
integrated more easily with existing product schemas if the
celebrity schemas match the product schemas (Lynch and
Schuler 1994). Both theories assume enhanced effects in
the case of congruence. Accordingly, several studies have
supported the product match- up hypothe sis (Erdoga n
1999). We thus hypothesize larger effects for object–en-
dorser congruence compared to incongruence.
H6: Congruent celebrity endorsers evoke stronger endorse-
ments ef fects when compared to incongruent ones.
Endorsement explicitness Explicitness can broadly be cate-
gorized into two modes: implicit and explicit endorsements.
Whereas implicit endorsements refer to situations where ce-
lebrities simply use an object or merely appear jointly without
overtly announcing their support (BI use this object^;*Miller
and Allen 2012), explicit endorsements refer to situations
where celebrities overtly express their support for an object
(BI endorse this object^; *Miller and Allen 2012). To the best
of our knowledge, no study has ever compared both modes;
instead, they have researched either implicit or explicit en-
dorsements. Though effects have been found with both
modes, one mode may be more effective than the other (im-
plicit: e.g., *Miller and Allen 2012;explicit:*Deanand
Biswas 2001; *Friedman and Friedman 1979). According to
Russell and Stern (2006), consumers infer the celebrity–object
association to be of greater strength if celebrities explicitly
express their support, signaling commitment and reliability.
In addition, consumers may not even realize that an object is
endorsed if the endorsement is too subtle. We consequently
propose that explicit endorsements are more effective that
implicit ones.
H7: Explicit endorsements evoke stronger effects than
implicit ones.
Endorsement frequency Celebrities may also vary in their
endorsement frequency. Consumers are highly likely to en-
counter celebrity endorsements multiple times via various me-
dia channels, including TV, billboards, print advertising, ra-
dio, and the Internet. Research on classical conditioning sug-
gests that effects may occur as early as a single pairing of a
celebrity with an endorsed object (e.g., Ambroise et al. 2014;
Gorn 1982). However, other research suggests that effects
tend to be greater the greater the number of pairings. For
instance, Stuart et al. (1987) increased the number of pairings
from one to three, to ten, and eventually to twenty, revealing a
steady increase in effectiveness. Although these results do not
directly refer to celebrity endorsements, similar effects can be
as
sumed because celebrity endorsements are often seen as a
certain type of classical conditioning (e.g., *Chen et al. 2012).
The following hypothesis is proposed:
H8: Celebrity endorsem ent effects increase with in-
creased endorsement exposure.
Familiarity of the endorsed object Next to the celebrity, the
endorsed object itself may impact endorsement effectiveness
(*Friedman and Friedman 1979). For instance, researchers
assume stronger effects, with decreasing familiarity with an
endorsed object (*Miller and Allen 2012). Object familiarity
can be understood as the number of object-related experiences
accumulated by a consumer (Alba and Hutchinson 1987).
These experiences can be obtained directly and indirectly,
such as through celebrity endorsements (Kent and Allen
1994). The more familiar a person is with an object, the more
comprehensive his or her knowledge structures can become
(Keller 2012). Given that consumers already possess a rich
network of associations representing an object, attitudes, and
behavi or appear more difficult to change (C acioppo et al.
1992). Accordingly, Ambroise et al. (2014)reportedstronger
celebrity endorsement effects with unfamiliar compared to
familiar brands. Similarly, Shimp et al. (1991) showed the
likelihood of conditioning effects for unknown or moderately
known objects, but not for well-known ones. We consequently
propose stronger celebrity endorsement effects for unfamiliar
objects when compared to familiar ones.
H9: Celebrity endorsement effects are stronger for unfa-
miliar objects when compared to familiar ones.
J. of the Acad. Mark. Sci. (2017) 45:55–75 59