CHAPTER 4

Celebrity Endorsers and Social Media Influencers

How It Works

Using Influencers to Destigmatize Mental Health

The app Headspace has a mission to “improve the health and happiness of the world.” Headspace is there to guide and partner with people on their mental health journey and tries to destigmatize mental health issues while also providing the benefits of things like meditation. This became increasingly important as the pandemic hit in 2020, and anxiety levels hit all-time high for many people. And while the destigmatization was happening before Covid, it was accelerated. Additionally, people got much more comfortable with digital products in the health space. Now people are returning to normal, albeit a new normal, by establishing new routines and new habits.

Headspace worked with influencer marketing agency Collectively to design a content creator strategy. The campaign focused on Headspace’s sleep products, where the goal was to increase consideration of the app. During the pandemic, mental health became an interesting issue as some celebrities did not show much empathy and connection with everyday people. But some influencers did understand it and had authentic ways to bring empathy into content. One influencer was Chrissy Rutherford, who is a fashion and social media expert. She said that she has been a huge fan and user of Headspace for years, so when she partnered with them, her audience felt a seamless connection. “Headspace gave me the freedom to tell my story and how it resonates with me,” she said. She developed authentic content around it and experimented with new formats like Instagram’s Reels and also used Stories. It was important for the brand to loosen control on the content for this campaign, which Headspace easily did. Influencers were chosen based on how they were able to discuss the topic in an honest and vulnerable way. Collectively did a lot of research to identify the best options and also created a double opt in so that influencers were verified users of Headspace.

Success was measured in a variety of ways. Of course, the numbers play an important role, but Headspace also examined the online conversations in more depth and looked at whether the audiences were getting into the topic. This campaign showed that brands are welcoming authentic, relatable, and human dialogue to stand out.¹

How Influencer Marketing Works

While the research on influencer marketing and SMIs is in its infancy, the research on celebrity endorsers—and indeed, endorsement in general—has a long history. Several key theories from that research foundation may be used to explain “how” influencer marketing may work. This insight helps marketing managers to understand the underlying mechanisms which inform their decisions about campaign goals and objectives, influencer selection, campaign structure, and performance measurement. This insight also assists researchers to identify the major gaps in the literature as well as differences in traditional celebrities and SMIs as to how they affect consumer behavior. This chapter includes an overview of the major theories and what was learned within a celebrity endorsement context, what has been learned in an SMI context, and what gaps still exist when attempting to understand influencer marketing. Key theories include source credibility and source effects (including source attractiveness), matchup hypothesis/congruence, and the meaning transfer model.

Source Credibility and Source Effects

One of the most important questions to ask is how an endorser persuades someone to act. In other words, why that endorser? What makes he or she special? Source credibility (and relatedly source effects) is probably one of the most researched theories to explain how endorsers work.² Source credibility is commonly used to understand how a communicator’s positive characteristics affects the receiver’s acceptance of that message.³ While there are various contexts where source credibility is important as well as several ways to measure it, the most relevant definition relates to endorsers. Two conceptual models form that foundation: the source-credibility model,⁴ which highlights the importance of expertise and trustworthiness, and the source-attractiveness model⁵ which adds attractiveness, which depends on the source’s familiarity, similarity, likability, and attractiveness to the respondent. Early research⁶ defined source credibility as primarily a function of expertise, trustworthiness, and attractiveness. This model tends to be the most popular conceptualization of source credibility in the celebrity endorser literature. Specifically, source credibility is defined as follows:

Figure 4.1 highlights the components of source credibility.

Figure 4.1 Source credibility

Generally, it is assumed that celebrities who are attractive, credible, and trustworthy should yield positive consumer evaluations of the brand. However, it is rarely that simple. The research on the effect of celebrity endorsements on brand evaluations generally finds that persuasion is higher when expertise and attractiveness is high. Interestingly, trustworthiness has mixed effects on brand evaluations with some showing little to no effect,⁷ whereas some research has shown a positive effect of trustworthiness⁸ especially for low involvement consumers.⁹ It has been argued that the low trust could be a result of consumers knowing that celebrities are paid. The role of expertise is also mixed; some show the positive impact of expertise,¹⁰ whereas other research found a delayed, but not direct impact of expertise.¹¹ The impact of expertise depends on the product type¹² and on consumer type.¹³

There is a long history of research of marketing, beauty and attractiveness.¹⁴ Much the relevant work regarding attractiveness occurred between the mid-1970s and mid-1990s that acknowledged the power of attractiveness.¹⁵ But, physical attractiveness can also include other attributions such as likeability, familiarity, and liking.¹⁶ In many cases, recognition and celebrity status mattered more than physical attractiveness.¹⁷ Results are mixed when examining levels of celebrity liking (there have been few studies examining this specifically) and role of celebrity-brand fit.¹⁸ All said, there has been important research to show the power of source credibility and celebrity endorsers.

What about SMIs? The research on the effects of source credibility and source effects for SMI persuasion is relatively new. But researchers have started to shed light on how source credibility theories can be applied to SMIs and their effects on brand evaluations. Here is what we know.

Trust

Given that SMIs have a strong relationship with their followers, trust should play an important role in persuasion, especially those who are SMIs rather than celebrities.¹⁹ In fact, some research shows that trust was more important for SMIs than for celebrities in one of the only studies to directly compare the two endorser types.²⁰ Trust has a positive effect on brand evaluations,²¹ and trust was higher when there was product fit with the influencer.²² One issue that perhaps is of importance is the relationship between the influencer and followers, as well as who the influencer follows back. Research has examined the potential effects of trust and credibility by looking at the ratio of followers versus people the influencer follows in the assessment of an SMI. They found that this ratio matters and called for more investigation into whether a high number of followers (and a low number of accounts the SMI follows) could cause consumers to question whether the SMI is fact “real” and not a fake account.²³ Obviously, this has the potential to degrade trust. Other research found no relationship of trustworthiness on product interest.²⁴ There is some speculation that followers may be skeptical of the motives of even a trustworthy SMI.

All of that said, influencer marketing can be used to encourage trust. Trust can be a result of similarity (she or she is like me) or aspirational (I want to be like that person). Influencer marketing agency IZEA created a campaign with the Commonwealth of Kentucky called the “Mask Up KY Initiative.” The campaign used native Kentuckians at various influencer levels (nano-influencers to macro-influencers) across all social media platforms. The goal was to create content that spurred positive conversations about mask wearing during the pandemic (before the vaccine). The campaign also demonstrated how neighbors can stick together toward a common goal. This highlighted the impact of trust and influencers. The campaign results were 216 pieces of created content, 15 million people reached, and 38 million impressions at a cost of 83 cents per engagement.²⁵

Expertise

Expertise is an important criterion since most SMIs fit into a specialized genre or category based on their interests.²⁶ Perceptions of expertise was higher when there was product fit between the brand and the influencer.²⁷ But it was not that simple. Other research found no effect of expertise on brand evaluations, from either SMIs or celebrities²⁸ or on product interest.²⁹ Given that SMIs tend to create content in specific categories, more clarity on the role of expertise is warranted especially whether there is a difference based on the type of endorser (e.g., monomorphic vs. polymorphic).

Practically, however, expertise is important for some product categories. Cetaphil is a popular mass skincare brand. Research conducted by the brand found that 70 percent of Americans self-diagnose sensitive skin issues like dryness, irritation, and roughness. As such, Cetaphil launched a week-long campaign “Sensitive Skin Awareness Week in March 2021” and capitalized on DermTok,³⁰ a growing trend where dermatologists post videos to educate millions of people about skincare issues and try to debunk misguided ideas about skincare. Called skinfluencers, they have made a huge impact in the skincare space on social media. One top skinfluencer is skincare by Hyram, who has created videos on YouTube.

“Skinfluencers have really shifted the way that the skincare market and brands work with influencers. They used to have celebrities—like Jennifer Aniston—but now brands are shifting and saying that celebrities are not driving brand consideration and that influencers and dermatologists on social media that back our products are driving the market,” said Andrea Arias, associate brand manager for Cetaphil. Cetaphil aligned with a few of these dermatologists—Edward Zo and Melissa Alatorre—who are popular on TikTok and Instagram. “We saw a shift in the way that consumers are purchasing products and the way that we as brands think about brand consideration, so we did the first TikTok campaign to test and learn,” said Arias. “We split the campaign into two using skinfluencers and lifestyle influencers that were in the beauty category and who had some original content around it and ran the campaign October and November 2020.” This partnership with expert influencers has helped Cetaphil rise in popularity from number four to number three, primarily due to the interest of Generation Z and skincare. “Generation Z are very much skintellectuals and this has been reflected in the slowing of cosmetic sales and the increase of skin care,” said Claire Varge, head of beauty at WGSN. Cetaphil launched its first TikTok influencer campaign tapping 23 people to spotlight its cleaners. They also boosted the content. The fact that many of these influencers are experts emphasizes that the idea of expertise crucial criteria for some brands and campaigns.³¹ Arias added that “the campaign drove brand consideration of cleaners and we saw a spike in sales, and we saw positive metrics on our website. So, it was a good indicator that being in new platforms like TikTok is valuable.”³²

Attractiveness

It is no secret that many SMIs are attractive. In fact, for many (most), their looks played a direct role in their popularity. Early research examined the role of attractiveness and how it relates to brand evaluations and found that marketing managers should consider attractiveness when selecting SMIs (especially in relationship to the brand/product image). They found that attractiveness influences the perceived fit between the influencer and brand.³⁵ However, other research found no effect of attractiveness.³⁶

This indicates that more examination is needed in exactly what attractiveness is and means for SMIs, especially when there are other factors, such as authenticity at play. For celebrity endorsers, there is more to attractiveness so assuming at least some similarities, and diving deeper into the concept of attractiveness, there are other variables that are important to SMIs.

Liking

One aspect of attractiveness (and perhaps a large factor in the effectiveness of influence) is liking. In other words, is the endorser likable to audiences and potential customers? De Veirman and colleagues examined cues around popularity and opinion leadership. They found that the number of followers that an SMI has does affect consumers’ attitudes toward him or her by tapping into the issue of likability.³⁷ This is primarily explained by perceptions of popularity and in line with previous research, but it remains unclear whether liking translates into real opinion leadership (or influence). More research is needed on the role of liking for SMIs.

Identification and Similarity

Another consideration is the issue of identification or similarity. Seemingly this is one reason that SMIs are popular—that audiences can identify with them and can see themselves with them. Research shows that this does hold true. When examining other issues related to source credibility, consumers identified more with SMIs, felt more similar with them than celebrities, and were more willing to purchase from SMI.³⁸ But not much research has tackled the issue of identification, so more research is needed on the importance of similarity and identification between the SMI and his or her audience.

Despite that initiatives with SMIs are relatively new, there has been some strong research to examine how effective SMIs can be for brand building. However, there are several important gaps in understanding how SMIs can build brands. The bottom line is that more attention is needed. What do we need to learn? Well, trustworthiness was generally not important when using celebrity endorsers, but it would seem to be important to SMIs since they have closer and more trust-based relationships with their community. Additionally, the role of liking and the role of attractiveness may prove to be different with SMIs compared to celebrity endorsers. Specifically, these two variables could be prove to be more (liking) or less (attractiveness) important for SMIs than celebrity endorsers. One concept that is missing from celebrity endorsements is the role of authenticity. Given the differences between celebrities and SMIs, what (if any) is the role of authenticity for SMIs? This seems to be important for SMIs but is not considered for celebrity endorsers. Last, given why SMIs are chosen, are there other variables to consider? More on that later. But before we do, let’s look at a few other theories that are important to celebrity endorsement and could prove useful to influencer marketing. Figure 4.2 highlights the components of source attractiveness.

Figure 4.2 Aspects of source attractiveness

Match Up Hypothesis and the Role of Congruence

Early research on the impact of source credibility (trust, expertise, and attractiveness specifically) suggests that any celebrity who fits this description can endorse a product effectively.³⁹ This has been challenged because it does not explain why some endorsers are more or less effective than others. This led to research on the match up hypothesis, which suggested that an endorser would be most effective if there was “congruence” or “fit” among the endorser, product, and target audience. In other words, there should be a way that they match up to create effective persuasion. The process underlying the matchup hypothesis can be explained with social adaptation theory⁴⁰ and schema theory.⁴¹ Both assume that congruence will yield positive effects on brand evaluations. Congruence consists of relevancy, defined as the “degree to which the information held in the celebrity endorser contributes a clear, lucid representation of the communicated theme,”⁴² and expectancy, defined as the degree to which stimuli fit some expected pattern or theme. Congruence is dependent on the specific situation—the product and the endorser in each situation. Research has shown that when consumers feel that there is a match between the endorser and the product, it results in more positive brand evaluations.⁴³ In fact, the issue of congruence can be so important that it has effects on other variables in both direct and indirect ways.⁴⁴ Other research took a more holistic view of image and congruence.⁴⁵ While the results are mixed, generally higher congruence is more effective than lower congruence.

The matchup hypothesis has been used to examine SMIs. Matchup is important to both the brand and the SMI. The concept of matchup is particularly important for SMIs given they regularly communicate with their followers, establishing relationships and para-social interactions (discussed later in this chapter).⁴⁶ Much of the communication between SMI and their followers is not persuasive in nature; so, to maintain trust and authenticity, SMIs need to be careful about who they partner with and what they say in messaging. But what about the relationship with followers? It can also be argued that given the “special characteristics of social media influencers might diminish the importance of the perceived fit” thus developing a halo effect due to the nature of para-social relationships. Research shows that matchup between the SMI and brand has a positive impact on the image of the SMI and brand evaluations, thus showing that even for the SMI, congruence is important. Researchers argued this is important given that when reaching out to new audiences, some brands choose SMIs that may not be good fits for their brands. They found that congruence is important for perceptions of expertise and trustworthiness for the endorser as well. SMIs need to consider their fit with brands to avoid damaging their relationships with followers. If they do happen to work with a brand that is slightly incongruent, SMIs need to create a personal post to generate para-social interaction.⁴⁷

That said, in a direct comparison between SMIs and celebrities, some researchers have found that contrary to expectations about the role of fit, they did not find any relationship. Fit did not explain the relationship between type of endorser (SMI vs. celebrity) and expertise or trust.⁴⁸ Despite the lack of a relationship, they did find that respondents identified with more, felt more liking, and trusted SMIs over than celebrities, showing the potential for SMIs as effective brand endorsers.

Meaning Transfer Model

While the previous theoretical foundation of source credibility and match up hypothesis are important, these do not capture the endorser’s broader cultural meaning.⁴⁹ In this model, the endorser (in earlier cases, the celebrity) was part of the broader pop culture and brought some of that to the endorser-brand relationship. The aim was to demonstrate the transfer of nonevaluative traits from the celebrity to the brand.⁵⁰ Cultural anthropologist Grant McCracken argues celebrities provide meaning through their work and their celebrity status. Audiences respond to the endorser’s identity based on both evaluative and nonevaluative traits, which is accumulated over time through their performances. As such, these traits are persuasive because they represent broader meanings.⁵¹ There is not necessarily an explicit relationship between the celebrity meanings and the product since they are created through symbolic cues and advertising. But consumers then recognize the cultural meanings in both the product and the endorser and “transfer meaning” between the two. If this transfer happens, endorser-brand relationships can be really effective. A great example is Nike and Michael Jordan. Michael Jordan is a great basketball player known around the globe. When he began a deep, decades long relationship in the 1980s with shoe brand Nike, who was trying to establish itself in basketball, the relationship not only proved to be amazing from a consumer perspective but was worth millions to Nike’s bottom line. Interestingly, despite being one of the most widely cited articles, only a few studies have attempted to test McCracken’s meaning transfer model.⁵² Newer research has extended the meaning transfer model to the process transfer model, suggesting that the way consumers evaluate an endorser may be more sophisticated given the variety of both celebrities and SMIs that are used.⁵³ It attempts to supplement existing models to provide a more comprehensive understanding of endorser effects. Other research used meaning transfer to examine the effect of attractiveness and congruence between the SMI and the brand and found positive evaluations of the brand. This research shows that both attractiveness and congruence are important to evaluation effectiveness and shows that this congruence facilitates meaning transfer from the SMI to the brand.⁵⁴

Overall, there are several key theories from celebrity endorsement research that can be explored to shed additional light on how influencer marketing works. That said, given the unique nature of SMIs relative to traditional celebrities—specifically that they build their brand completely online, at least initially—there are several other key theories that need more examination. Additionally, it is important to understand more about the audience. Who are they? What works best with them? Are there differences across gender, ages, other variables? Given that influencer marketing is particularly effective with younger audiences, how should SMIs build their following that maximizes their connections with their followers, specifically with millennials and Generation Z?

Generation Z and SMIs: Understanding Followers and Fans

Influencer marketing has changed how brands promote their products and services, and this new strategy is particularly effective with two audiences—millennials (aged 25–40) and Generation Z (13–24). More than three quarters of both generational cohorts follow influencers on social media and most say that this is the way to learn about new products. A Morning Consult Survey shows that both men and women are influenced by SMIs. In terms of topics, men prefer gaming and sports influencers, while women prefer beauty and fashion. They all follow influencers on social media for four primary reasons: inspiration and aspiration; voyeurism; to learn about trends; and they find them interesting and fun. Important traits about influencers include (very important + somewhat important):

Other traits included attractiveness-related traits such as personal and open, beautiful images, and physically attractive. Interestingly, having a large following was least important (29 percent). So, it is easy to see the connections between what is important to this audience and the characteristics of source credibility discussed earlier.

Millennials and Generation Z also act on recommendations from SMIs. This is how 88 percent of them learn about products and 56 percent have made a purchase directly due to an SMI post. They also trust an influencer’s recommendations about products. While friends and family are still the most trusted sources to give advice, SMIs are ranked higher in trust than celebrities. Knowledge is also an important characteristic in the effectiveness of SMIs. In terms of social media platforms, YouTube is more popular with men while Instagram reigns supreme with women.

Interestingly, many young Americans want to be influencers! Fifty four percent said they would become an influencer if given the opportunity and 12 percent already consider themselves to be one. Sixty-six percent they would be willing to post sponsored content for money, especially when it comes to travel, events, and memes but primarily if they liked the product. Figure 4.3 illustrates a description of Generation Z.

Figure 4.3 Generation Z⁵⁵

Given the importance of SMIs to this audience, there has been little attention on the effect of target audience factors on celebrity persuasion and SMI impact. Earlier research on celebrities found no age-related differences in the audience’s perceptions of them. However, that research did not consider the new definition of celebrities and the role of social media. This is important given that SMIs are most popular with millennials and Generation Z, who don’t seem to differentiate the concept of a “traditional” celebrity from that of SMIs. Research on gender differences with celebrity persuasion has also been mixed and limited. Additionally, no studies really examine cross-cultural differences, or race/ethnicity differences, or whether and how celebrities and SMIs can persuade consumers and where those differences may lie. So, what do we know about how SMIs develop engaging relationships with their followers?

Connecting SMIs and Their Followers

The influencer’s relationship with the audience is the most valuable element when brands consider SMI selection. The personal nature of social media enables celebrities and influencers to initiate a quasi, two-way relationship with followers. This is quite different from the top down, one-way communication between celebrities and audience through mass media like television and movies. An important part of social media is that it enables users to interact with SMIs and brands through likes, shares, and comments that seem to create a sense of friendship. While the interaction is far from reciprocal and differs from how people would interact with friends and family, the idea of being closer to SMIs is one major difference in the current ways that endorsement works. And SMIs tend to spend more time cultivating those relationships since their brand is built entirely online. These are called para-social relationships. Para-social relationships⁵⁶ have been studied in various contexts (e.g., television hosts, soap opera stars, and movie stars). This is essentially where an audience member (or follower in this case) feels a connection to a media personality (in this case, an SMI). It is an intimate relationship—a socioemotional bond that occurs that is now more easily facilitated due to the nature of social media platforms and the ubiquity of social media usage.⁵⁷ Recently, multiple studies have examined the para-social relationships between social media users and SMIs⁵⁸ and report strong para-social relationships between audience and their favorite SMIs, especially with higher levels of online social interaction.

Para-social relationships are an important concept when examining the influence of SMIs. Researchers⁵⁹ investigated the determinants and role of source credibility in para-social relationships between SMIs and their followers, as well as their followers’ interests in the products endorsed by the influencer. Specifically, followers’ perceived attractiveness and perceived similarity to the influencer and fairness with how influencers communicated with followers positively affected the strength of these para-social relationships between SMI and followers. It also increases their interest in endorsed products. Interestingly, perceived expertise and trustworthiness did not relate to the strength of para-social relationships. Perhaps, being an expert or being trustworthy did not seem to help cultivate this type of relationship between the SMI and followers. Practically, the effect of para-social relationships can be powerful. Addi McCauley of IZEA has seen campaigns where audiences feel very close to the influencer treating and communicating with them like friends. “Personally, after the birth of my daughter, I follow a postpartum nurse from St. Louis. She constantly posts about mom tips and mom hacks and is constantly posting where people have direct messaged her. They are tagged on her Instagram. I purchase all of the bath products for my daughter because of her recommendations.” In her case, the allure was a mix of trust and expertise because this influencer is a nurse and mom of three and is relatable. “You literally talk to these people the way you would a friend,” she added.⁶⁰

There are several factors that are related to para-social relationships. Self-disclosure is a vital component of para-social relationships and serves to build relationships. The degree of self-disclosure from the influencer—that he or she disclosed personal aspects of their lives online—affected para-social relationship development with celebrity endorsers online.⁶¹ Celebrities who did not disclose personal details on their social media sites were seen as lacking in honesty and authenticity. Something—even negative disclosure—is better than nothing. Negative self-disclosure can enhance para-social relationships and greater authenticity.⁶² Celebrity self-disclosure online, particularly professional self-disclosure (information about work and professional lives) and personal self-disclosure (personal details), affects para-social relations.⁶³ Self-disclosure is an important step toward building a relationship and is also an important first step to create social presence.

Social presence is the perception associated with being psychologically involved in the interaction with the another in a mediated environment.⁶⁴ Essentially, it gets to the environment that must be present for audiences to feel a connection to the influencer online. Factors include media/technology-related factors, user factors, and social factors—all of which determine the degree of social presence. Social factors appear to be the most valuable to understanding influencer marketing. Social factors include followers’ social response toward media. The importance of social factors such as informal relationships and trust,⁶⁵ humor,⁶⁶ and perceived self-disclosure⁶⁷ have been found to induce strong social presence in other types of online environments. When celebrities share and communicate aspects of their lives, followers tend to feel that celebrities were present in their lives. Social presence also facilitates more positive para-social relationships.

Another way to increase para-social relationships is to do things to maximize authenticity—which is about being perceived as representing one’s true self on the screen.⁶⁸ SMIs can cultivate two types of authenticity. Passionate authenticity is maximized when SMIs can create and post content that is interesting and fits their style and identity. Transparent authenticity refers to the fact-based information about the product being endorsed and the disclosure information about the relationship between the SMI and the brand. Both are important indicators that an SMI is being authentic with followers.⁶⁹

While much has been researched in celebrity endorsement literature and applied to SMIs, there is still much to examine. Influencer marketing is in its relative infancy as companies determine the best way to find influencers and match them with brands. Additionally, we know very little how audiences really use influencer marketing and how the influencer process really works, especially with younger audiences. We also have yet to examine some of the unintended consequences on both audiences (e.g., fear of missing out [FOMO], social comparison issues) and the influencers themselves (e.g., the difficulty of maintaining authenticity and privacy concerns). So, there is much to explore! The next chapter examines how to design effective campaigns, including goal setting and measurement, matching brands and influencers, and the best type of campaign to design for maximum effectiveness.