본 연구는 유튜브 온라인 구전 상황에서 소비자들이 정보원천인 유튜버의 공신력을 어떠한 기준으로 평가하고 이러한 기준이 구전효과에 어떠한 영향을 미치는 지에 대해 뷰티유튜버의 영상을 중심으로 고찰하였다. 유튜브는 소비자들이 온라인 정보검색 서비스 1위인 구글 다음으로 많이 찾는 매체이고 기존 온라인 구전의 특징과는 다른 특성인 구전 발신자 신원의 확실함을 지니고 있다는 특이점이 있다. 뷰티유튜버의 경우, 여성 소비자의 외모 관리 및 구매행동에 막강한 영향력을 행사하는 것으로 알려져 있다. 이로 인해 많은 화장품 회사들이 뷰티유튜버를 통해 자사 제품을 홍보하고 있으며 더 나아가 이들과의 협업을 통해 새로운 제품을 개발하고 또 이를 뷰티유튜버를 통해 홍보, 판매하고 있다. 따라서 유튜브 온라인 구전 상황에서 소비자들이 정보원천의 공신력을 어떻게 판단하고 이것이 구전효과에 어떠한 영향을 미치는 지를 알아보는 것은 필요하다. 이를 위해 심층면접 방법을 통해 정보원천의 공신력 판단 기준과 이에 따른 구전효과에 대해 구체적으로 살펴보고자 한다. 심층면접 결과, 소비자들은 뷰티유튜버 영상을 시청하는 상황에서 정보원천의 공신력을 판단하는 자신만의 기준을 가지고 있었다. 정보원천의 공신력은 크게 전문성, 신뢰성, 매력성으로 구분될 수 있다. 먼저 전문성에 영향을 미치는 요소는 언어적 표현, 화장기술, 유명도, 협찬으로 나타났다. 다음으로, 신뢰성에 영향을 미치는 요소는 유명도, 제품에 대한 태도, 콘텐츠의 일관성, 다른 시청자들의 동조, 협찬으로 나타났다. 마지막으로 매력성에 영향을 미치는 요소는 개성, 친근감, 유사성, 애호성으로 나타났다. 또한 자신이 판단한 정보원천의 공신력에 따라 다른 구전효과가 존재하는 것으로 확인되었다. 특히 유사성이 높을수록 높은 구전효과를 가지고 있었다. 본 연구는 정성적 연구를 통하여 유튜브라는 특수한 구전상황에서 소비자들이 판단하는 정보원천의 공신력 기준에 대해 알아보고 이를 유형화하였다는데 의의가 있다. 또한 이를 통해 유튜브 온라인 구전 상황에서 소비자에 대한 이해를 높이고 더 바람직한 소비환경 마련을 위해 기여할 수 있다. 이러한 연구결과는 실무적 측면에서 시사점을 제공하고 이에 대한 이해의 폭을 넓혀주는 계기가 될 것이다.

YouTube is the second most popular online information search service for consumers, after Google. In addition, YouTube has the characteristics of both traditional e-WOM and offline WOM, but also has its own unique characteristics. In addition, beauty YouTubers are known to have a strong influence on the appearance management and purchasing behavior of female consumers, and therefore, many cosmetics companies promote their products through these YouTubers, develop new products through collaboration with them, and promote and sell these new products through those Beauty YouTubers. Accordingly, this study aims to suggest consumer criteria of source credibility, and influences of source credibility, to their word-of-mouth effect, within the context of YouTube e-WOM. The major research findings are as follows: First, consumers had their own criteria for determining source credibility in the context of watching Beauty YouTubers: expertise, trustworthiness and attractiveness. Source credibility can be largely divided into expertise, trustworthiness and attractiveness. Viewers consider both their own and another viewers' evaluations to determine expertise; they assess a YouTuber's linguistic expressions and makeup techniques in judging that expertise, and comprehensively consider famousness and their sponsorships. Linguistic expressions refer to the terms or words that Beauty YouTubers use to describe products; all interviewees rated YouTubers highly professional when they mentioned chemical ingredients and professional or unique terms. Interviewees also felt that Beauty YouTubers have more expertise if the latter have excellent makeup techniques, with judgements based on analyses of their and other people’s appearance. The majority of the interviewers recognized the number of subscribers and views of the content as their level of famousness and judges their expertise by these. Interviewers use sponsorships as another criterion to judge Beauty YouTubers' expertise. Sponsorships serve as an element to enhance perceived expertise, but if viewers think YouTubers only advertise sponsored products, they tend to feel their expertise is low. Viewers personally evaluate a Beauty YouTuber's attitude toward products and the consistency of content uploaded. Beauty YouTubers are thought to demonstrate high trustworthiness when they show a sincere attitude toward the products they review. The reliability of Beauty YouTubers who focus solely on beauty content is, notably, higher than those who upload both beauty and other content. An appropriate numbers of subscribers (a subjective criterion) and views were also found by the majority to have a positive impact on trustworthiness, with trust increasing if the number of subscribers is reasonable according to the interviewee's judgment; otherwise, trust declined. Viewers judge Beauty YouTubers' trustworthiness by referring to comments on videos, as well as just viewing the videos themselves. When a Beauty YouTuber's assessment of products has won acclaim from those who post comments, their credibility increased, but if the video and comments are conflicting, the YouTubers are found less reliable. The sponsorships also affect viewers' trustworthiness for beauty YouTubers. Most of them answer that receiving sponsorship undermines their trust of beauty YouTubers but when beauty YouTubers mentioned both positive and negative information about sponsorship products, trustworthiness turned out to be higher. Factors affecting attractiveness were individuality, interactivity, similarity and liking. The individuality of Beauty YouTubers is sensed in a variety of ways, including appearance, voice, and personality; viewers judge Beauty YouTubers' attractiveness based on their own tastes, and become fans. For this reason, the individuality of the YouTuber serves as an important criterion for viewers selecting sources of information. Interactivity is felt through a YouTuber's attitude, voice, speech, and communication skills; the more friendly one feels, the more attractive one is judged. High attractiveness can also be judged by viewers' perception of their own similarities with Beauty YouTubers. Liking is a natural creative act, based on interactivity and similarity, as well as affection; it creates viewers' own favorite YouTubers, and thus their source of information. There is a difference in strength or function between the three important factors in assessing source credibility, leading to oral effects. Interviewees viewed trustworthiness as more important than expertise, and attractiveness has been shown to be the first factor influencing interviewees' continuous consumption of content; no matter how useful that content, it is not consumed in the first place if the viewer is not attracted to the YouTuber. Degrees of importance vary between these criteria, but in the end all three factors are added to create oral effects on the use and recommendation of Beauty YouTubers. However, purchase intention is not only influenced by the positive attitude about the product, but also by external factors - including possible access to the product - and internal factors - including similarities in consumers' economic conditions, and makeup skills. Therefore, even if oral effects exist according to the source credibility of a Beauty YouTuber, other internal and external elements are involved in the process of connecting their intention to purchase them. The results of this study suggest a few implications, the first being that Beauty YouTubers must recognize that viewers watch them due to their attractiveness, and should strive to maintain it. In addition, because they think they are getting vivid reviews and know-how from ordinary people, viewers believe in and trust the information obtained from Beauty YouTubers, and the latter should only feature sponsored products that fit their image. Channels should not become too commercialized, and if sponsored, YouTubers should address both advantages and disadvantages of products. It is also important to interact with viewers through comments on the video, as viewers communicate with each other in and judge the trustworthiness of these videos by the comments. Second, the beauty industry needs to develop effective marketing strategies. Consumers are not only responding to Beauty YouTubers' attractiveness, but also their expertise and trustworthiness. The industry can promote products through YouTubers who are similar to their target markets, since similarity plays a role in purchase intention. In addition, as consumers generally have a negative perception of sponsorships, it is necessary to change the way they sponsor YouTubers, in order to more easily reach consumers. Consumer education, with practical standards for expertise and trustworthiness, can teach viewers how to evaluate the information currently available on YouTube, and understand how this can lead to purchases. Even though they likely know there is commercial deception, consumers should still be told that they may purchase goods due to their perceptions of YouTubers. Practical standards for expertise and trustworthiness should also be provided, and reduction of excessive sponsorship or products in placement (PPL) currently within TV programs is necessary to reduce consumer damage.