A Literature Analysis on the Relationship between AI Influencers’ Perceived Credibility and Purchase Intention: Product-Endorser Fit with the Brand as a Moderator

The study investigates the impact of AI influencers’ perceived credibility (AIIs’PC ) on Chinese consumers’ purchase intention (PI), as well as the moderating effect of product -endorse fit with the brand (PEFB) on the relationship between AIIs’PC and PI. AIIs’PC refers to the level of trust consumers have in AI influencers and their perception of the reliability and authenticity of the information, recommendations, or product endorsements provided by them. AII s’ PC includes attractiveness, trustworthiness, and expertise. PEFB denotes the relevance or congruence between the product endorser (AI influencer) and the brand being promoted. This alignment involves whether the image, traits, and values of the product endorser align with the positioning, image, and values of the brand. Previous literature on human influencer marketing has indicated that consumers’ purchase intention is influenced by AIIs’PC and PEFB, but the research results remain mixed and inconclusive. Specifically, there is a lack of relevant research on the moderating effect of PEFB on the relationship between AIIs’PC and PI in the context of AI influencer marketing. Therefore, this study discusses the relationship between AIIs’PC and PI and the moderating effect of PEFB on the relationship between AIIs’PC and PI. Ultimately, this research can enrich the existing body of knowledge on consumer behavior in the context of AI influencer marketing.


Introduction
In recent years, the development of technologies such as Artificial Intelligence (AI) has significantly reshaped the interaction between consumers and brands, as well as the shopping experience (Flavián et al., 2019).These new technologies have also given rise to a new form of influencer marketing, known as AI influencers.These AI influencers are computergenerated virtual personalities with a wide-reaching influence on social media, playing a role similar to that of human influencers in marketing, such as brand endorsements.AI influencers are primarily constructed from five technological modules (natural language processing, image recognition, voice recognition, problem-solving, and machine learning).The first three modules are used to gather information.Natural language processing extracts linguistic meaning from consumer text such as social media posts, direct messages, or tweets (Kietzmann, et al., 2018).Image recognition and voice recognition collect consumer-posted images, videos, and audio information on social media.AI influencers utilize problem-solving to construct various responses to address consumer inquiries and continuously enhance their ability to resolve consumer issues through machine learning in each interaction with consumers (Kietzmann et al., 2018).
AI influencers are increasingly being used as alternatives to human influencers in corporate advertising campaigns (Franke et al., 2023).Currently, 63% of companies globally plan to use AI influencers in their influencer campaigns (Goudswaard, 2023).Los Angelesbased startup Brud manages three prominent AI influencers: Lil Miquela, Bermuda, and Blawko, ranked first, fifth, and sixth, respectively, in HypeAuditor's 2019 Annual Instagram Virtual Influencer Rankings (Baklanov, 2019).Lil Miquela is described in her Instagram bio as a "robot seeking change" and is perhaps the most well-known.In 2018, she was named one of Time magazine's most influential people on the internet and was described as a fashion idol promoting luxury brands like Prada, Balenciaga, and Kenzo (Time, 2018).Bermuda is a character self-proclaimed as the "queen of robots," while Blawko endorses more mainstream brands such as Netflix, Nike, and Del Taco (Baklanov, 2019).With the emergence of more international AI influencers, numerous companies in China have introduced over 30 local AI influencers, with many internet companies participating in various financing activities for the AI influencer industry (Ji, 2021).One of the most famous Chinese AI influencers, Ayayi, created by Ranmaitech in 2021, has become a brand ambassador for international renowned brands in the Chinese region, such as NIKE, Dyson, and M.A.C.Currently, AI influencers have become traffic owners on Chinese online platforms such as Weibo (Chinese version of Twitter) and Douyin (Chinese version of TikTok) (Ji, 2021).Overall, 62.2% of Chinese netizens believe that AI influencer marketing campaigns can enhance their purchase intentions (IQiyi, 2019).
Similar to their human counterparts, AI influencers publish various content, build connections and relationships, and generate excitement and audience engagement (Huang et al., 2022).However, AI influencers do not have the opportunity to test products or their features.Therefore, their recommendations are not based on experience, raising questions about potential sources of success based on perceived legitimacy (Huang et al., 2022).Understanding how audiences perceive AI influencers is crucial in determining the effectiveness of influencer marketing mechanisms and the impact of AI influencers on shaping consumer attitudes and purchase intentions.The process by which AI influencers guide consumer trust, brand attitudes, and purchase intentions is complex and dynamic (Wibawa et al., 2022).Therefore, in order to provide valuable insights for marketers and relevant practitioners, it is necessary to study how AI influencers influence purchase intention in marketing campaigns.

Conceptual Model
Figure 1 illustrates the hypothesized model linking the relationship between AI influencers' perceived credibility, product-endorser fit with the brand, and purchase intention.Attractiveness, trustworthiness and expertise will be used to measure AI influencers' perceived credibility in this conceptual model.Finally, it should be noted that due to the influence of various factors on purchase intention, it is not feasible to encompass all measurement scales in just one study.

AI Influencers' Perceived Credibility
In the digital age, with the overwhelming influence of scattered marketing media messages, consumers find it challenging to discern which content is trustworthy when making purchase decisions or seeking buying advice from opinion leaders (AI influencers) (Davidaviciene & Paliulis, 2019).The credibility of a communicator or message source is an important factor in its persuasiveness (Hovland & Weiss, 1951).Therefore, AI influencers' perceived credibility has become crucial for consumers to mitigate perceived risks in the buying process (Aytuna, 2019).According to the study of Hovland and Weiss, Kelman and Hovland (1953); Ohanian (1990), AI influencers' perceived credibility have three dimensions: attractiveness, trustworthiness and expertise.

Attractiveness
In many studies, attractiveness has been acknowledged and utilized as a key dimension of source credibility (McGuire, 1985;Ohanian, 1990Ohanian, , 1991)).In the literature, source attractiveness is described as a multidimensional construct, with these sub-dimensions being crucial for message effectiveness.Some early studies employed terms such as "attractive," "beautiful," "charismatic," and "sophisticated" to characterize attractiveness (Patzer, 1983).Physical attractiveness is generally considered a significant aspect of forming initial impressions of an individual (Ohanian, 1990).In certain industries, particularly in the fashion and cosmetics sectors, attractiveness is primarily interpreted in terms of physical appearance (Djafarova & Trofimenko, 2018).Therefore, in this study, attractiveness refers to the physical attractiveness of the AI influencer as perceived by consumers.Numerous studies had demonstrated that physically attractive sources were more effective in altering consumer viewpoints and attitudes (Chaiken, 1979) and in influencing purchase intentions (Till & Busler, 2000).Ladhari et al (2020) discovered in their investigation of beauty vloggers that physical attractiveness significantly impacts the purchase intention for the products they endorse.
Several previous studies examined the relationship between attractiveness and purchase intention in different research contexts (e.g., AI influencer and human influencer).In the context of human influencer marketing, Aytuna (2019) found a significant and positive relationship between attractiveness and purchase intention in a study on the impact of human influencers on the purchasing intentions of Millennials.Similarly, Torres et al (2019) also observed a positive effect of attractiveness on purchase intention.However, the study conducted by Lou and Yuan (2019) did not reveal a positive or significant relationship between attractiveness and purchase intention.
In the context of AI influencer marketing, Kim (2022) suggested that the stronger the appeal of AI promoters to consumers, the higher their willingness to accept information.This is because the attractiveness of AI promoters as sources of information enhances the effectiveness of communication between the brand and the consumer, thereby increasing the willingness of the recipient of the information to purchase the brand's products (Robinson, 2020).Chiu and Ho (2023) confirmed this viewpoint and found a positively significant relationship between attractiveness and purchase intention.However, Kim and Park (2023) demonstrated that attractiveness had no direct effect on purchase intention, but the relationship became significant when mediated by imitation desire and brand attachment.Similarly, Yap and Ismail (2022) also found that attractiveness was not directly related to purchase intention.Given the mixed and inconclusive findings on the relationship between attractiveness and purchase intention, further investigation is necessary in the context of AI influencers in China.

Trustworthiness
Trustworthiness is another dimension of source credibility.According to Hovland et al. (1953), trustworthiness refers to "the degree of confidence and acceptance the audience has in the speaker and the message."Friedman et al (1976) defined credibility as "the solemn, trustworthy, and honest attributes possessed by the speaker and observed by consumers."McCracken (1989, p. 311) proposed an updated definition as "the perceived validity of claims made by the information provider."Therefore, as AI influencers function as information providers, trustworthiness can be interpreted in this study's research context as the level of trust consumers have in AI influencers.
Trustworthiness represents consumers' expression of expectations for the authenticity of advertising information (Logan et al., 2012).It pertains to the level of trust consumers possess when evaluating information (Cuesta-Valiño et al., 2020).In other words, without credibility, there is no trust.On social media platforms, information from credible sources holds the power to alter recipients' attitudes, representing the effectiveness of communication (Cuesta-Valiño et al., 2020;De Veirman et al., 2017).Essentially, credibility promotes effective communication through brand endorsements (Shimp, 2000).Considering influencers as trustworthy brand endorsers is critical as it increases the likelihood of purchasing the endorsed brand (Shimp, 2000).
Numerous studies (McGinnies & Ward, 1980;Pornpitakpan, 2003aPornpitakpan, , 2004) ) had shown that credibility positively influences attitude change and purchase intention.According to Djafarova and Matson (2021), trustworthiness is a key factor in determining influencer credibility.When consumers trust an influencer, they are more likely to believe their recommendations or endorsements, which could influence their perceptions and purchasing habits for specific products (Singh et al., 2020;Wiedmann & Mettenheim, 2020).
In the context of human influencer studies, many studies have confirmed that trustworthiness significantly affects purchase intention (Aytuna, 2019;Ki & Kim, 2019;Lou & Yuan, 2019).On the contrary, Tiwari et al. (2023) found that there was no positive significant relationship between trustworthiness and purchase intention.Additionally, Drossaert (2023) conducted a comparative study aiming to understand whether there were differences in perceived trustworthiness and frankness between human influencers and AI influencers and whether these two types of influencers had different effects on consumer purchase intention.The study found that the trustworthiness of AI influencers had a positive impact on consumers' purchase intention (Drossaert, 2023).However, this result contradicts the findings of Chiu and Ho (2023).In a comparative study of three types of influencers (traditional celebrities, micro-influencers, and AI influencers), Chiu and Ho (2023) found that the trustworthiness of AI influencers did not affect consumer purchase intention.Chiu and Ho (2023) suggested that Gen Z consumers may not trust AI influencers as they come from a fictional world and cannot try the products they promote (e.g., beauty products) and provide honest opinions.The findings by Chiu and Ho (2023) provide new evidence that, even though Gen Z is the primary target audience for virtual influencers, their impact on consumer attitudes and behaviors remains uncertain.Based on this discussion, the findings are still mixed and contradictory, and therefore there is a need to investigate further the relationship between trustworthiness and purchase intention in the context of AI influencer in China.

Expertise
According to Kelman and Hovland (1953), expertise is described as "the extent to which the communicator is perceived as a source of valid assertions.It refers to the knowledge, experience, or skill that the endorser possesses."McCracken (1989, p.311) provides a similar definition inspired by Kelman and Hovland (1953), that is "perceived as having the capacity to make valid assertions."In the context of celebrity endorsements, a more recent definition describes expertise as "the extent to which the endorser is perceived to possess sufficient knowledge, experience, or skill to endorse a product" (Van der Waldt et al., 2011, p.104).Indeed, for each definition, the key focus is not on being an actual expert but on being perceived as one by the target audience (Kelman & Hovland, 1953;Ohanian, 1991).Therefore, in the context of this study, expertise can be understood as whether consumers perceive the AI influencer as an expert in the product (endorsed or recommended by the AI influencer).
In the realm of celebrity endorsements, expertise is considered the most crucial dimension for effective endorsements (Daneshvary & Schwer, 2000).Expertise reflects the competent image a celebrity displays when endorsing a particular brand or product.For instance, athletes, doctors, or lawyers can endorse products related to their respective professions (Ohanian, 1991).Friedman and Friedman's (1979) research suggests that consumers prefer to purchase high-tech and pricey products if endorsed by a professional celebrity.Celebrities with a higher level of expertise are expected to be more persuasive than those perceived to have a lower level of expertise (Aaker & Myers, 1987) and are more likely to stimulate purchase intentions (Erdogan, 1999;Ohanian, 1991).
In the context of human influencer endorsements, AlFarraj et al. ( 2021) explored the influence of influencer credibility on consumer purchase intentions in the beauty and skincare industry.The study confirmed that expertise had no significant effect on purchase intentions (AlFarraj et al., 2021).AlFarraj et al. (2021) explained that this result was due to "relatively limited experience in the field of makeup and skincare, not enough to be a factor" (p.368).Similarly, Lou and Yuan (2019) also found no significant relationship between expertise and purchase intentions.However, Aytuna (2019) found that the influencer's expertise is crucial in explaining consumer responses, including purchase intentions.He pointed out that consumers are more likely to consider purchasing a product endorsed by a source they perceive to have knowledge and experience in a certain product category (Aytuna, 2019).
In the context of AI influencer endorsements, Formentini (2020) suggests that the expertise of AI influencers enhances the perceived credibility of their image among consumers, thereby improving their attitudes towards the brand and stimulating purchase motivation.However, this assertion contradicts other research findings.Huang et al. (2022) analyzed the impact of AI influencer characteristics on consumer purchase intentions for branded apparel and found no significant relationship between expertise and consumer purchase intentions.Huang et al. (2022) speculated that this result might be due to the fact that clothing is a necessity; the expertise disparity among clothing endorsers may not be a significant consideration for consumers of clothing.Young online consumers seem to boost brand awareness through other means.Apparently, this explanation seems plausible as consumers tend to rely on the endorser's knowledge, skills, and expertise when the brand is not a necessity but rather a technological or high-end category (El Hedhli et al., 2021).Similarly, Chiu and Ho (2023) analyzed the impact of AI influencer's expertise on the purchase intentions of Generation Z consumers in China endorsing beauty products (soap).The study found that the expertise of AI influencers does not directly affect consumer purchase intentions.This result also supports Healy's (2021) viewpoint that consumers question whether AI influencers provide genuine opinions, testimonials, or content for the products they endorse, as they do not actually use the products they endorse, unlike human influencers.This poses a significant challenge for AI influencers endorsing beauty products (Chiu & Ho, 2023).Since the findings on relationship between expertise and purchase intention were mixed and inconclusive, there is a need to further investigate the relationship between expertise and purchase intention in the context of AI influencer in China.

Product-Endorser Fit with the Brand
Product-endorser fit with the brand (PEFB) refers to the similarity or consistency between the endorser and the product or brand, within a particular context of endorsement (Bergkvist et al., 2016;Schouten et al., 2020).According to Rifon et al. (2004), if consumers perceive a strong match between the endorsed brand and the endorser, they may attribute their main motivation to the endorsement, enhancing its effectiveness (Bergkvist et al., 2016).When a meaningful match is established between the endorser and the product, a strong relevance between the endorser and the product exists (Misra & Beatty, 1990).Most studies have also shown that increased alignment between the celebrity and the brand correlates with a higher probability of positive consumer responses to the endorsement (Fleck et al., 2012;Kahle & Homer, 1985;Lynch & Schuler, 1994;Till & Busler, 2000).Similarly, Choi and Rifon (2012) argue that the higher the consistency between the celebrity/product, the following outcomes are expected: (a) more positive attitudes towards the advertisement; (b) more positive attitudes towards the brand; and (c) a greater inclination to purchase the brand.
Diverging from leveraging traditional celebrities through traditional media such as TV shows, movies, and magazines to enhance brand product value, companies are turning to social media influencers, who have gained fame by showcasing themselves as product experts (Khamis et al., 2017;Marwick, 2015).Influencers use their credibility and product evaluations to positively influence fans' purchase intentions (Wei & Lu, 2013).However, Bower and Landreth (2001) suggest that having a highly credible endorser is not always effective for all brand categories, emphasizing the importance of fit in endorsement strategies.Indeed, for influencers, the fit of the product endorser may have a more significant impact on consumers' willingness than celebrity endorsers (Kim & Park, 2023).Because influencers successfully brand themselves as representatives of specific domains, such as "beauty bloggers," and distribute details about products to their fans Balog et al (2008), the association between the product and the endorser may be more accessible.Consequently, compared to celebrities, influencers endorsing products that do not match their specialization are more likely to receive negative reviews, and only endorsements closely aligned with their areas of interest will be regarded as credible sources of information by the audience, positively impacting consumer purchase intentions (Schouten et al., 2020).
Furthermore, previous literature has also examined the moderating effect of PEFB on the relationship between AI influencers' perceived credibility and purchase intention.Aytuna (2019) found that PEFB moderated the relationship between attractiveness and purchase intention.However, in a study on the relationship between AI influencer attractiveness and consumer purchase intention, Kim and Park (2023) found that under low PEFB (below one standard deviation of the mean), there was no significant association between attractiveness and purchase intention.However, under high PEFB (above one standard deviation of the mean), a significant and positive correlation was found between attractiveness and purchase intention.Therefore, PEFB partially moderated the relationship between attractiveness and purchase intention.
In terms of the moderating effect of PEFB on the relationship between trustworthiness and purchase intention, only a few studies have directly investigated this effect (Aytuna, 2019), with most research focusing on verifying the direct influence of PEFB on purchase intention (Santos & Azevedo, 2019).Aytuna (2019) discovered the moderating effect of PEFB on the relationship between trustworthiness and purchase intention in a study on how Instagram influencers affect purchase intention, using multiple linear regression analysis.Similarly, in the context of the limited literature on the moderating effect of PEFB on the relationship between expertise and purchase intention, Aytuna (2019) found the moderating effect of PEFB on the relationship between expertise and purchase intention.Given the scarcity of topic-relevant literature and the inconsistency of previous research findings, it is necessary to further investigate the moderating effect of PEFB on the relationship between AI influencers' perceived credibility and purchase intention.

Purchase Intention
"Purchase intention" refers to the likelihood of consumers acquiring a certain product (Fishbein & Ajzen, 1977).Similarly, according to the definition provided by Spears and Singh (2004), purchase intention represents an individual's conscious plan or effort to purchase a specific brand.In short, purchase intention can be understood as the likelihood that a consumer may intend to purchase a specific product or service in the future (Wu et al., 2011).Morwitz (2012) have noted that purchase intention is considered a primary predictor of consumer potential purchase behavior.Marketers widely utilize purchase intention in research not only to forecast sales but also to estimate production quantities based on demand, test brand and product concepts, and launch (Silk & Urban, 1978), advertising research (MacKenzie et al., 1986), market segmentation (Sewall, 1981), brand evaluation, and brand extensions (Spears & Singh, 2004).Some studies on consumer behavior indicate that consumer purchase intentions are influenced by various factors such as past experiences Barber et al (2012), product type Morwitz (2012), popularity Park et al (2007), quality andcredibility O'Reilly &Marx (2011), word of mouth and brand awareness Lafferty et al (2002), brand knowledge and loyalty Khan et al (2012), opinions of family and friends Price & Feick (1984), and other generated content from consumer evaluations Burnkrant & Cousineau (1975), timing choices (Morwitz, Steckel, & Gupta, 2007).Nevertheless, this study will not consider these factors.The research aim of this study is to explore the influence of AI influencers on consumer purchase intention.Therefore, consumers' perception of AI influencers' credibility will be the primary consideration factor.Drawing from the previous literature, this study will treat purchase intention as the dependent variable.

Conclusion
This article reviews relevant literature in the field of influencer marketing, emphasizing the positive impact of AI influencers' perceived credibility on consumer purchase intention.The authors propose that under conditions of product consistency, AI influencers' perceived credibility can significantly strengthen consumer purchase intention.Given the limited research investigating the moderating effect of PEFB on the relationship between AI influencers' perceived credibility and purchase intention, this paper aims to fill this research gap.The study proposed in this paper is of significant importance for practitioners and scholars alike.Firstly, for marketing professionals, understanding the influence of AI influencers on consumer purchase intent can guide them in effectively leveraging AI influencers for product promotion and marketing activities.This research can provide them with valuable insights to develop more targeted influencer marketing strategies and activities, thereby enhancing product sales and market share.Secondly, for scholars, this research can broaden the understanding of consumer behavior in the current context of AI applications.Ultimately, such thought relies on more detailed empirical research in China.