VLOGGER AND BRAND CREDIBILITY PERCEPTION: A SYSTEMATIC LITERATURE REVIEW OF ENDORSEMENT EFFECTIVENESS IN YOUTUBE VLOGS

ABSTRACT


Introduction
The presence of online platforms and social media in recent years has become a new means of communication for the community (Li, Lai, & Lin, 2017).However, nowadays, social media significantly affects the development of the marketing and advertising industry.Historically, advertising services have always involved audience monetization in the business industry, and businesspeople will choose what media platforms can reach more audiences (Appel, Grewal, Hadi, & Stephen, 2020).Social media such as Instagram, TikTok, Facebook, and YouTube have become a part of people's lives that cannot be separated.According to datareportal.com, in 2022, the number of social media users in Indonesia will reach 191.4 million, equivalent to 68.9% of the country's total population.Compared to 2021, the number of social media users in Indonesia increased by 12.6% or 21 million users (Rania, 2018).
Among various types of social media, YouTube is the social media that has the most active users.At the beginning of 2022, YouTube users in Indonesia reached 139 million.This means that the reach of YouTube ads in Indonesia in 2022 is equivalent to 50% of the total population of Indonesia.In recent years, video blog content (Vlog) has become the most popular content on YouTube, especially among young people.On average, around 3.7 million new videos are uploaded to YouTube every day, and about 694 thousand videos are watched every minute.This figure is higher than the number of Netflix streams, which is 452 thousand per minute.
Various types of vlog content, such as beauty, food, fashion, games, and others, have become trends spread all over the world.Like other social media platforms, the high consumption of YouTube vlogs among the public has created a new trend for content creators.Online celebrity, influencer, or key opinion leader (KOL) is now a term for content creators on social media.According to Freberg and Graham (2011), social media influencers are individuals or groups who use social media platforms such as YouTube to create and share uploads or content about various things with their followers (Burke, 2017).The popularity of these influencers is judged by the number of viewers of the content and subscribers/followers of their channel accounts.
From a marketing perspective, the popularity gained by online celebrities has created a new way to reach audiences through social media platforms.Vloggers or influencers with high popularity are considered able to influence or persuade their followers and audience.Today, using vloggers in communication and marketing campaigns on YouTube is increasingly popular, especially in several industries such as beauty/fashion, health/fitness, travel/lifestyle, food/drink, and entertainment.From big brands to MSME products, vlog content from famous vloggers became a medium for advertising or what is now commonly referred to as endorsement practices (Burke, 2017).
Endorsements are carried out by famous vloggers such as Ria Ricis and Atta Halilintar to vloggers who are not too prominent.Nowadays, brand owners can easily find the type of vlog or vlogger content that suits their brand (Chang & Ko, 2016).Around 321 thousand accounts or channels on YouTube alone have over one hundred thousand subscribers.Brand owners can find vloggers they want to work with through various sources.The socialbuzz.com website page provides vlogger information quite wholly, such as vlogger names, types of content, number of subscribers to card rates, or endorsement fees (SocialBuzz, n.d.).
In terms of vloggers, this endorsement practice also provides new opportunities to gain profits in addition to YouTube ads.For brands, of course, the presence of famous vloggers who become influencers can offer unique alternatives in advertising and marketing at a more affordable price compared to advertisements on TV or in newspapers.Therefore, this study examines the effectiveness of endorsements in YouTube vlogs and explores how the perception of vlogger credibility as a content provider and source of product information from a brand is built, as well as how the content of this endorsement vlog affects brand credibility.

Research Methods
This research was carried out through systematic literature review or systematic literature review methods by following various stages in the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) model (Page et al., 2021).

Search strategy
The search strategy consists of scientific writings on the Google Scholar page until April 3, 2023.The search was conducted with the keywords "vlog endorsement," "perception of vlogger credibility," and "perception of brand credibility."The results found 557 documents related to keywords, and after that, the selection process was conducted independently.

Study Selection and Inclusion/Exclusion Criteria
Eligibility determination for inclusion and exclusion categories is based on the study's objectives.The inclusion criteria were journal articles related to the effectiveness of vlog endorsements on YouTube about the perception of vloggers and brand credibility as a reference in research.The inclusion criteria in this study also include articles published after 2016 (the last seven years), and articles must be written in English or Indonesian.The exclusion criteria consist of documents that cannot be uploaded thoroughly, scientific writings other than journals (books, dissertations, theses, magazines, etc.), journal articles published before 2016, and those written in other foreign languages.

Data Extraction and Synthesis
After selecting the included journal articles, extraction was carried out on the following elements: title, author, year, vlog endorsement perception of vlogger, and brand credibility.A thematic analysis was carried out to synthesize different research to learn about the effectiveness of endorsements on YouTube vlogs.This is done to identify data and patterns in each study and categorize research based on a theme.The thematic analysis process uses the stages proposed by Virginia Braun and Victoria Clarke, namely: 1.Data recognition phase (familiarising data) 2. Generating initial codes 3. Mencari tema (searching for themes) 4. Reviewing themes 5. Defining and naming themes 6. Producing report In each journal article, the analysis focused on data related to the research question: How is the perceived credibility of vloggers as a provider of content and a source of information about the product of a brand built, and how does the content of this endorsement vlog affect brand credibility?.
The data extraction and preparation are done in Microsoft Excel sheets focusing on each research question.Data related to similar contexts are further grouped under their respective themes.The results are compared with the original data to check consistency, clarity, and coherence.

Results and Discussion
Based on searches using three keywords, namely vlog endorsement, perception of vlogger credibility, and perception of brand credibility, 16 articles were generated.Furthermore, after identifying articles based on title/abstract, out of the 16 articles, 11 articles were obtained that did not meet the inclusion and exclusion criteria.Furthermore, a selection process was carried out by reading the entire article.Of the 5 articles, there was 1 article that could not be used because the text of the article could not be downloaded completely.The final result of the literature selection process, as many as 4 articles were selected and met all specified criteria (see Figure 1).
In the first journal, entitled "Thanks for watching," The effectiveness of YouTube vlog endorsements, Munnukka, Maityb, Reinikainena, and Luoma-ahoa (2019) conducted a study with an experimental method to test the effectiveness of brand endorsement in vlogs by assessing the role of audience participation, parasocial relationships, and valence of vlog endorsements on the perception of vlogger credibility and brand attitude.
The study used 203 respondents as followers/subscribers to vlogs consisting of adult respondents aged 26-35.Experimental research was conducted using pre-test and post-test techniques by displaying vlog videos to respondents.The vlog content was carefully considered based on matching the characteristics of the United States respondents and using a vlog featuring only one vlogger.The results of this study show that vlogs with a high level of audience participation/followers can increase brand endorsement acceptance by increasing the audience's perceived credibility of vloggers.
The positive relationship between audience participation and the perception of vlogger credibility mediated by parasocial relationships increases the perception of vlogger credibility.It has a positive effect on the brand endorsement displayed.Manukka et al. (2019) stated that parasocial interactions between followers and vloggers in vlog content have helped increase vlogger credibility.The ability of vloggers to provide reciprocal perceptions can increase audience trust in vloggers and greater acceptance of brand endorsements.So, it can be concluded that the effectiveness of endorsements on YouTube vlogs can increase with the high audience participation in vlog content.Increasing the perception of vlogger credibility can also strengthen brand endorsement acceptance among consumers (Munnukka et al., 2019).
In the second journal, entitled "The Effects of Vlogger Credibility as Marketing Media on Brand Awareness to Customer Purchase Intention," Anas Nugraha and Refius Pradipta Setyanto (2018) conducted a study using a survey method to analyze the influence of YouTube vlogger credibility on brand awareness and consumer buying interest.
The survey was conducted using a non-probability sampling technique of active people on YouTube social media and resulted in 150 questionnaire responses.The collected data is then analyzed using SPSS and AMOS applications and the Structural Equation Model (SEM) to simultaneously test a series of relatively complex connections.
The results of Nugraha and Setyanto's research show that the perception of increased vlogger credibility among consumers has increased brand awareness.This means that the higher the level of credibility, the higher the brand awareness.Research shows that vlogger Arief Muhammad is highly popular.Confidence, interesting vlog content, and its characteristics for vlogger Arief Muhammad.It makes people admit that he has a good attitude and makes people believe everything he says.The survey results show that, in general, vlogger Arief Muhammad has met 4 indicators of credibility perception, and the survey results also state that consumers feel that trust increases credibility and awareness of the endorsed brand, namely Traveloka (Nugraha & Setyanto, 2018).
In the third journal, entitled "Celebrity vs. Influencer Endorsements in Advertising: The Role of Identification, credibility, and Product-Endorser Fit", Alexander P. Schouten, Loes Janssen, and Maegan Verspaget (2019) conducted a study by conducting experiments to test the effectiveness of endorsements between celebrities and online influencers, namely vloggers and celebrities.This study used two experimental designs: the type of endorsement (celebrity vs influencer) and the suitability of endorsement products (good fit vs poor fit).After filling out the questionnaire, all experimental participants were randomly assigned two stimuli.
From the experimental results, Schouten et al. stated that the perception of participants' similarity was higher than that of influencers.This happens because of the view of vloggers or celebrities who are similar to 'ordinary people' compared to traditional celebrities.Trust and expertise will be critical mediators between the endorser and the effectiveness of the endorsement.Therefore, in this study, the perception of influencer credibility is higher than traditional celebrities because the feelings are more similar to those consumers feel towards influencers, so the influencers' endorsement becomes more trusted.As a result, credibility and purchase intent towards products endorsed by influencers are higher (Schouten et al., 2020).
In the fourth journal, entitled "The Influence of Beauty Vlog on Perceived Source Credibility and Purchase Intention," Yaumul Rahmi, Laras Sekarasih, and Bertina Sjabadhyni ( 2017) conducted a study using experimental methods to examine the influence of vlogger credibility perception on consumer purchase intent.Ninety-eight women aged 18-34 years who have experience using YouTube were participants in the study.This study used pre-test and post-test experimental designs.A beauty brand video (Wardah matte lip cream) is the experimental product used.There were two videos used, namely vlogs about beauty reviews, lip cream product vlogs (liquid lipstick), and brand advertising videos; then participants were divided into both groups.
The results of Rahmi et al.'s research show that compared to commercial advertising (using traditional celebrities), beauty vlog endorsements do not significantly influence consumer purchase intentions.This is made possible by consumer perceptions in collectivistic cultural countries such as Indonesia that regard traditional celebrities as a more credible source of information.The perception of credibility towards beauty vloggers is also possible due to the low familiarity between experimental participants and beauty vloggers.Out of 50 experimental participants, only 11 knew vloggers.
This certainly impacts participants' perceptions of vloggers' trust and expertise, an essential dimension in the perception of credibility.However, the results of this study also state that brand endorsement of beauty vloggers through vlog reviews can be an instrument to "improve" brand reputation or consumer disappointment with the product quality compared to increasing consumer purchase intention (Rahmi et al., 2017).
These four pieces of literature result in an understanding that YouTube vlogs are effective in endorsement practices.Vloggers can serve as a new form of digital advertising that can influence brand recognition and purchase intent.However, in understanding the effectiveness of endorsements in YouTube vlogs, the first, second, and third journal articles agree that the perception of vlogger credibility is key to the effectiveness of endorsements.In the research of Manukka et al. (2017), the audience's credibility perception of vloggers will increase with the high interaction of the contractor in the vlog (Munnukka et al., 2019).
According to the research of Nugraha et al. (2018), the perception of credibility towards vloggers increases when the expertise, trust, and attractiveness of vloggers stand out.Vloggers with good characteristics and interesting and unique content are proven to increase trust and credibility with vloggers (Nugraha & Setyanto, 2018).This is supported by research by Schouten et al. (2020), which states that trust from the basis of similarity and familiarity felt by the audience is essential in increasing the perception of vlogger credibility (Schouten et al., 2020).Based on the perspective of credibility perception, the dimensions of trust, expertise, and attractiveness are the main dimensions in building credibility, and this perception of credibility is crucial in seeing the effectiveness of endorsements.
When the perception of vlogger credibility is high, it will significantly affect brand credibility.From the perspective of endorsement, a vlogger or endorser is present as a person who represents the brand.In addition, an endorser will also transfer the quality recognition of a product to consumers (Abeza et al., 2017).So, in other words, the credibility of a vlogger will also be transferred to the endorsed and then accepted by the audience as a brand with high credibility, just like an endorser.
Although the research of Rahmi et al. shows that in Indonesia, the effectiveness of endorsements on YouTube vlogs still needs to be studied further.The collectivistic culture in Indonesia still considers traditional celebrities (such as soap opera artists, movies, or advertising stars) more credible sources than vloggers.However, the effectiveness of this endorsement is still very likely, especially if you pay attention to aspects of familiarity or consumer introduction to vloggers and similarities between vloggers and brands (Rahmi et al., 2017).As in the research of Nugraha et al. (2018), vlogger Arief Muhammad, as an endorser, has a very good perception of credibility.He managed to gain consumer trust through his expertise and authenticity by becoming a vlogger so that the perception of credibility can increase the credibility and awareness of the brand (Nugraha & Setyanto, 2018).
Therefore, although endorsements are now a new alternative in marketing communications, companies need to ensure that consumers can consider endorsements on YouTube vlogs positive.For endorsements on YouTube vlogs to be influential for brands, companies also need to review the purpose of the ad.According to Lin (2015), endorsements are effectively used to improve brand image, awareness, positioning, and attention and increase consumer purchase intention (Lin et al., 2015).In increasing the effectiveness of endorsements on YouTube vlogs, companies must also ensure similarities between brands and vloggers and not limit vloggers from creating according to their characteristics to maintain audience trust.Because the authenticity and characteristics of vloggers are the key to success and effectiveness in vlog endorsements.

Conclusion
Endorsements are currently a new alternative trend in marketing communications.The presence of online celebrities or influencers has encouraged the effectiveness of endorsements on social media.As the most widely used social media platform by audiences today, YouTube has produced various creativity in making videos.Vlogs or video blogs have become the most popular video content for people as the most popular content.The presence of famous vloggers then encourages endorsement activities on YouTube vlogs.From world-class, well-known brands to local brands using YouTube vlogger services for product endorsements.
From the results of this systematic literature review, it was produced that endorsements on YouTube are currently quite effective.However, the effectiveness of this endorsement also needs to consider the perception of the vlogger's credibility.The perception of a vlogger's credibility will increase based on authenticity, trustworthiness, and attractiveness.Vlog content that can display these three things will increase the perception of vlogger credibility in the eyes of the audience.This is important because the vlogger's credibility will affect the brand's credibility.Meanwhile, as an endorser, the vlogger will represent the brand and transfer its quality and credibility to the endorsed product.