The impact of human and virtual endorsements on advertising effectiveness: a comparative analysis based on different information appeals

Heuristic-systematic model

In the existing research on advertising endorsements, scholars typically explain the positive and negative effects of brand endorsement types through the theories of anthropomorphism and the information source model. However, these two theoretical logics are inconsistent, and approaching from a single perspective can lead to contradictory research conclusions. Therefore, it is necessary to adopt a consistent logic and explain the effects of anthropomorphism and information source simultaneously through a unified theoretical framework. This study believes that the Heuristic-Systematic Model can solve the aforementioned issues.

The heuristic-analytic dual-process model delves into how personal motivation, ability, and involvement collectively influence judgments and decisions (Kahneman, 2011). This theory offers a distinct theoretical perspective on how individuals receive and process information, evaluate its authenticity and validity, and execute decision-making processes based on this understanding (Eagly and Chaiken, 1993). Within the framework of heuristic-analytic dual-process model Theory, the Heuristic-Systematic Model further elucidates two distinct modes of information processing. This model specifies under what circumstances individuals opt for heuristic or systematic information processing. Specifically, individuals with limited information processing capabilities, insufficient motivation, or low involvement are more likely to rely on heuristic processing. Conversely, when conditions permit, individuals tend to engage in deeper systematic processing (Chaiken, 1980). When information receivers choose heuristic processing, they require less cognitive effort, relying primarily on easily accessible decision criteria for swift and practical judgments. On the other hand, if information receivers opt for systematic processing, they need to invest significant cognitive effort (Chaiken, 1980), examining all relevant information thoroughly and assessing information validity through comprehensive analysis to make persuasive judgments (Zhang et al. 2014). In existing research on advertising endorsement, scholars often explain the positive and negative effects of brand endorsement types through anthropomorphic theory and the information source model. However, these two theoretical logics are inconsistent, leading to contradictory research conclusions when approached from a single perspective. The Heuristic-Systematic Model well illustrates the process of consumer information processing and serves as a favorable tool for exploring the differences in how consumers handle persuasive information conveyed by different endorsers.

In addition, by reviewing the relevant literature, we found that when the endorser’s characteristics match the advertising message, the effectiveness of the advertisement is enhanced (Zhu et al. 2022). Therefore, this study establishes the moderating factor of advertising appeal (rational advertising vs. emotional advertising). Numerous studies have shown that rational appeal advertisements rely on consumers to engage in systematic processing, expending more significant cognitive effort to process information arguments to exert persuasive effects; whereas emotional appeal advertisements depend on consumers to engage in heuristic processing, establishing emotional connections with consumers to enhance persuasive effects (Kunkel et al. 2019). Therefore, this study approaches from the perspective of advertising appeal to verify the moderating role of advertising appeal in the impact of endorser type on advertising effectiveness.

In summary, this study employs the theoretical framework of the Heuristic-Systematic Model to simultaneously explain both the anthropomorphic effect and the information source model. The research model constructed in this paper takes endorser type (human vs. virtual endorsement) as the independent variable, advertising claims (rational appeals vs. emotional appeals) as the moderating variable, brand trust as the mediating variable, and advertising effectiveness as the dependent variable.

Research on the correlation between types of brand endorsers and advertising effectiveness

Initially, McCracken defined the essence of celebrity endorsement, referring to individuals who utilize their public recognition and trust to promote consumer goods in advertisements and enhance the appeal of products through their influence (McCracken, 1989). Subsequently, brand endorsers in the industry have been recognized as an effective sales strategy. By selecting appropriate endorsers, brands can effectively expand their influence, strengthen their brand image, promote brand communication, and enhance the market competitiveness of enterprises (Ambroise and Albert, 2020). In early studies, brand endorsers mainly focused on individuals with significant popularity, such as celebrities and idols, who achieved recognition for the brand and its products through their own usage and experience. This influenced the public perception of the brand, forming a positive marketing effect (Mowen and Brown, 1981). Later, some scholars pointed out that the concept of endorsers should not be limited to celebrities and idols. Experts, third-party endorsers, industry celebrities, typical consumers, and internet celebrities can also be included in the category of endorsers. Although the definition of endorsers has been continuously enriched, for a long time, this category was mainly limited to real individual identities. Most studies still focused on human endorsement to explore related commercial value, legal regulations, communication effects, and other issues.

The advent of the digital age has given rise to the development of virtual reality technology, and the role of virtual endorsement has gradually gained academic attention. The academic and industry have high expectations for virtual endorsement, because it can make up for the ethical problems of human endorsers to a certain extent, and maintain the consistency of virtual self-identity (Tan and Liew, 2020). In fact, early scholar Aaker emphasized that virtual and cartoon images have the same brand communication effect as social celebrities. He attributed virtual and anthropomorphic images to the concept of endorsers (Aaker and Keller, 1990). Chinese scholar Zhimin Zhou also emphasized in his research that brand endorsers are not necessarily specific people. Consumers can also transfer emotions to brands through virtual images, groups, animals, etc. These virtual images can also provide information services for products or brands. Therefore, the extent of anthropomorphism is deemed the paramount factor influencing consumers’ attitudes toward and trust in virtual spokespersons (Huang et al. 2022). This anthropomorphic quality can amplify the perceived presence of brand spokespersons (Pelau et al. 2021), elevate consumer satisfaction (Kim and Kim, 2021), foster brand goodwill, and mitigate uncertainty during the consumption journey (Crolic et al. 2022; Cui, 2022). Furthermore, within themarketing realm, pertinent research underscores the significant impact of the degree of personification of virtual spokespeople on brand trust, emotional response, purchase intent, and behavior (Huang et al. 2022). Additionally, some studies delve into the direct comparison and distinctions between real-person and virtual endorsements, positing that these endorsement types exert differential effects on consumer trust and anxiety levels (Sands et al. 2022; Deng and Jiang, 2023).

According to existing research, the differences between virtual endorsement and human endorsement are manifested in multiple aspects. For instance, the plasticity of virtual images allows for more creative freedom, which can fully enhance the alignment between virtual endorsement and product brands. As an anthropomorphic virtual image, virtual endorsement avoids scandals similar to those involving celebrities, which could tarnish the brand image. Consumers are intrigued by the virtual nature of virtual endorsement, providing them with a robust interactive experience and sensory stimulation (Garretson and Burton, 2005). Some scholars have explored the development of virtual endorsement from the perspectives of appearance and attribution of mind, pointing out that although virtual endorsers share physical and behavioral characteristics similar to humans, they still differ from human endorsers. In terms of thought patterns, consumers generally perceive virtual endorsers as computer-generated images, thus their impact is not as profound or dynamic as that of human endorsers (Müller et al. 2021). Research has also focused on the challenges and risks of virtual endorsement. For example, virtual endorsers do not pose economic and reputational risks to brands, offering stability and security. However, studies have shown that when human endorsers face crises, consumers often attribute negative effects to the endorser themselves and may even sympathize with the brand. In contrast, for virtual endorsers, consumers tend to attribute negative impacts to the application and transfer negative emotions to similar endorsers (Thomas and Fowler, 2021). Regarding trust in virtual endorsers, there are conflicting conclusions in relevant studies. Some studies suggest that virtual endorsers cannot guarantee product transparency, making it difficult to attribute responsibility when issues arise. However, other studies confirm that consumers tend to trust virtual endorsers (Gerlich, 2023).

Based on existing research on endorser types and advertising effectiveness, which focuses on the impact of different types of celebrity idols on advertising effectiveness, some studies analyze brand endorsers as advertising information sources. For instance, conflicting endorser combinations often yield better advertising and marketing effects. The nationality of endorsers has a particular influence on advertising effectiveness, and factors such as the endorser’s own characteristics (professionalism, popularity, credibility, attractiveness, etc.) and related internal moral levels all affect advertising marketing effectiveness, positively influencing consumers’ brand attitudes and purchase intentions (Bearden and Netemeyer, 1999). Regarding different types of endorsers, some studies have confirmed that various types of endorsers possess distinct traits, leading to different impact effects. The higher the attractiveness of the endorser and the similarity to consumers, as well as the audience’s familiarity with the endorser, the greater the influence on brand identity, resulting in varying advertising attitudes, brand attitudes, and purchase intentions (Wright, 2016). According to the aforementioned related research, there are inconsistent conclusions in the academic community regarding current studies on virtual and human endorsements. This is because human and virtual endorsements exhibit different characteristics, leading to varied advertising effects. Furthermore, with the increasing application and promotion of virtual digital humans in brand marketing, consumers’ attitudes and responses towards virtual endorsements, as well as deeper variable conditions, still require further exploration. Based on this, the following research hypothesis is proposed in this study:

H1: There is a significant difference in the impact of endorser type (virtual endorsement vs. human endorsement) on advertising effectiveness.

The mediating effect of brand trust

As a psychological dependence, trust plays a crucial role in the interaction between consumers and brands. Based on the perception of brand reliability and friendliness, brand trust serves as the foundation for consumers to choose a brand and spread word-of-mouth. Existing research has proven that brand trust is influenced by various factors, such as product quality, brand image, and service level. Regarding the relationship between brand endorsers and brand trust, scholars Byrne and Breen pointed out that celebrity endorsers can attach their own popularity, professionalism, reputation, and other values to the brand. Brands can take advantage of this to shorten the time to establish their own credibility, reputation, and popularity (Byrne et al. 1968). Scholar Biswas believes that demonstrating the quality and attributes of a product through endorsers can, to a certain extent, form brand associations in consumers’ minds, increasing their sense of trust and identification with the product (Biswas et al. 2006). Currently, there is sufficient research on human endorsements and brand trust, while empirical research on virtual endorsements and brand trust is still in its initial stages. The initial research on virtual endorsements and trust can be traced back to 1996 when scholars Dotz and Morton proposed that virtual endorsements can generate a sense of trust among consumers, thereby influencing their brand loyalty and consumption behavior (Dotz et al. 1996). Subsequently, trust has emerged as a pivotal concern within the realm of virtual endorsement marketing (Cornelius et al. 2023). Yet, the existing research presents conflicting findings regarding the impact of virtual endorsers on brand trust. For instance, pertinent studies have demonstrated that the authenticity of virtual endorsements diverges from that of human endorsements. In instances where a product malfunctions, the transparency of accountability becomes blurred, thereby leading to diminished trust in virtual endorsements (Robinson, 2020). Conversely, there are also studies that refute this conclusion, with evidence suggesting that consumers exhibit a preference for novel endorsement types, which foster trust and engender positive impressions of brands (Gerlich, 2023). Consequently, this study explores how human and virtual endorsements influence brand trust under varying advertising demands.

Judith et al. established a conceptual model. Through empirical research, they proved that the nostalgia, professionalism, and product relevance of virtual endorsements affect the formation of consumer brand trust, thereby influencing product attitudes and purchase intentions (Judith et al. 2005). Other studies have also shown that the sincerity and excitement traits presented by virtual endorsements can produce better advertising and marketing effects. Specifically, these traits not only directly affect brand attitudes but also indirectly influence brand attitudes through brand trust (Sweeney and Swait, 2008). Some studies start from the perceived authenticity of virtual endorsements, indicating that when virtual endorsements exhibit images of sincerity, professionalism, earnestness, and integrity, they can more effectively stimulate consumers’ sense of brand attachment. In recent studies, it has been pointed out that when brands use virtual endorsements, consumers experience curiosity and a sense of novelty, enhancing their favorable impression of advertising and marketing, leading to positive consumer evaluations and attitudes (Franke et al. 2023). Therefore, brand trust plays a crucial role in consumers’ cognitive process of forming a brand image, serving as an emotional bond between advertising marketing and consumers. As a symbol of brand emotion and visual culture, brand endorsers can influence consumers’ cognitive processes and further shape their attitudes towards the brand. Consumers with high brand trust are more likely to produce positive advertising and marketing effects. Based on this, the following research hypothesis is proposed in this study:

H2: Brand trust has a mediating effect in the influence of brand endorser types on advertising effectiveness.

The moderating effect of advertising claims on the relationship between endorser type and brand trust

This paper employs the Heuristic-Systematic Model to explain how advertising claims (rational and emotional appeals) moderate the advertising effectiveness of virtual idol endorsers. In related advertising marketing research, scholars have found that consumers often need to consume significant cognitive resources to process advertisements that employ rational appeals. This requires a logical, sensible, and more controlled approach to consider product attributes and brand information, forming rigorous and accurate information judgments (Chandrasekaran et al. 2018). During this process, consumers engage in active information-seeking behavior aimed at reducing uncertainty and confusion during the consumption process (Albers and Royne, 1999). Thus, whether an advertisement employs rational appeals depends on whether consumers have sufficient cognitive resources to systematically process advertising information (Swani, Brown and Milne, 2014). However, virtual endorsers typically lack real-life experiences and cultural backgrounds. Therefore, consumers often analogize the anthropomorphic characteristics of virtual endorsers to familiar human objects, reducing the difficulty of processing product information (Aggarwal and Mcgill, 2012).

The higher the level of processing of rational product information, the higher the consumers’ perceived utilitarian value of the product, forming a systematic product cognition and evaluation that enhances consumers’ memory and understanding of the product (Matthes et al. 2014). Therefore, advertisements featuring virtual endorsers can foster higher brand trust, leading to better advertising and marketing effects. On the other hand, when using human endorsements, consumers often focus their attention on celebrities due to their attractiveness, charm, and life experiences (Wang and Lin, 2011). During the advertising communication process, consumers may perceive product-related information as interfering information, affecting their positive perception of the product. Less rational product information processing may not achieve a good advertising and marketing effect (Stafford and Day, 1995).

Academic research on advertising claims, brand trust, and advertising effectiveness is relatively comprehensive. Besides the aforementioned rational appeals, scholars have conducted in-depth explorations of emotional appeals. For instance, some scholars believe that advertisements featuring human endorsements adopting emotional appeals can evoke consumers’ brand associations and feelings, thereby helping consumers recognize and understand the brand (Jang and Yoh, 2020). Other studies have shown that due to the lack of past experiences, authentic individual images, and relatively short existence, virtual endorsers are generally perceived as lacking emotions and the ability to control emotional experiences autonomously. Therefore, they exhibit lower credibility, and consumers have a lower acceptance and preference for the emotional content generated by virtual endorsers (Bakpayev et al. 2022).

Additionally, another type of advertising appeal, perceptual appeal, has begun to attract academic attention with the emergence of sensory marketing. In sensory marketing, increasingly more marketing strategies are achieving effectiveness through immersive experiences, as sensory cues influence consumers’ product evaluations and subsequent purchasing behaviors. However, some scholars have drawn different conclusions in studies related to virtual endorsements compared to human endorsements. Because virtual endorsers lack emotions, touch, smell, and taste, advertisements emphasizing sensory experiences through emotional appeals may reduce consumer preference to some extent. Although virtual endorsers can visually resemble humans, consumers still find it hard to believe that they can hear, see, or taste products, thereby decreasing brand trust (Zhou et al. 2024).

It can be seen that when individuals are faced with rational or emotionally-oriented advertisements, there are differences in how they process information, leading to different cognitive and emotional responses. In detail, rational appeal advertising requires consumers to invest more cognitive resources to analyze the logic and evidence in the information, with clear and specific information content to help consumers grasp the main points of information, and effectively reduce their doubts and uncertainties. On the contrary, advertisements with emotional appeal do not rely on the deep cognitive processing of consumers, but promote the formation of brand association and enhance the memory effect by touching the joy or sadness at the emotional level, so that consumers can intuitively feel the benefits brought by the product. However, in the existing research field, there is still a lack of clear and clear conclusions on how individual contact with various advertising endorsers affects advertising effectiveness in different contexts of rational and emotional advertising appeals.

Based on this, the following hypotheses are proposed in this study:

H3: Advertising appeals have a moderating effect on the influence of brand endorser type on advertising effectiveness.

H3a: When advertisements adopt rational appeals, compared to human endorsements, virtual endorsement advertisements increase consumer brand trust and have a significant positive impact on advertising effectiveness.

H3b: When advertisements adopt emotional appeals, compared to idol endorsements, human endorsement advertisements increase consumer brand trust and have a significant positive impact on advertising effectiveness.

Based on the above hypotheses, the research model of this paper is shown in the following Fig. 1: