The Effectiveness of Social Media Advertisement in The Indonesian Sneakers Industry: Application of The Extended Advertising Value Model

Objectives: This study aims to examine the effect of social media advertising values on customer engagement and purchase intention. Despite the unique features of social media ads to generate customer engagement, there is not much research that combines the advertising value model and interactivity component to understand the effectiveness of social media ads. Methodology: Questionnaires were distributed to followers of sneaker brands’ Instagram official account in Greater Jakarta who had bought the sneakers. There were 314 responses analyzed by PLS-SEM to answer the research questions. Finding: The results showed that customer engagement was influenced by credibility, entertainment, and interactivity of the advertisement, which eventually led to purchase intention. Furthermore, entertainment and interactivity advertising values had a direct influence on purchase intention. Conclusion: Brands should create entertaining and interactive ads to trigger engagement with their followers and stimulate their desire to purchase the products. Practical insights are provided based on these research findings.


INTRODUCTION
The rapid evolution of interactive technology has contributed to the growth of the online advertising market (Belanche et al., 2017) at a CAGR of 11.9%. Social media advertising should raise customers' awareness, knowledge, and perceptions toward brands that motivate them to buy the products. Social media enables brands to communicate with their customers in a more informative and interactive way (Alalwan, 2018).
While some studies in social media marketing have suggested that the impact of social media influencers have direct correlations with the intention of customer's purchases (e.g., Lim et al., 2017;Nurhandayani et al., 2019;Castillo & Fernández, 2019), Studies on the impact of social media advertising by brands towards customer purchase intention are still lacking. Referring to the advertising value theory, three elements of advertising value in traditional media consist of informativeness, entertainment, and irritation. Interactivity in social media advertising may increase customer engagement, and at the end generate stronger brand preferences and purchase intention (Alalwan, 2018). Even though customer engagement is essential for companies to manage their brand image, most studies of customer engagement are speculative in nature (Hollebeek et al., 2014). There are very limited studies looking at the correlation of advertising value and customer engagement (Chiang et al., 2017).
This study focuses on sneaker brands since customers of these products tend to use Instagram as a source of information for fashion products (Brandão et al., 2019;Casaló et al., 2017). Sneaker culture has permeated to mainstream culture over the last decade (Lux & Bug, 2018). The rise of the sneaker culture is proven by an estimated value of the global sneaker market of around $55 billion and the sneaker resale market has exploded to a substantial $2 billion in the US (Ma & Treiber, 2020). This research investigates the association between elements of social media advertising values and purchase intention through customer engagement in the context of sneakers brands advertising in Instagram.

Purchase Intention
Purchase intention is frequently used by academics as a key sign for predicting consumer behavior. In the same manner, marketers often consider purchase intention as an indicator of future purchase that triggers the company to urge customers to take actual purchase action (Wu et al., 2011). Purchase intention refers to the customer's willingness and motivation to purchase a product in the future. It measures one's likelihood to purchase (Calvo-Porral & Lévy-Mangin, 2017). When customers have a strong purchase intention, they are likely to hold a positive brand commitment that triggers them to make an actual purchase (Wu et al., 2011). Marketers must take advantage of social media platforms by utilizing informativeness and interactivity values by allowing customers to share their experience from purchasing and using the products. It has succeeded in strengthening customers' purchase intention and engagement (Choi & Rifon, 2002).

Social Media Advertisement Value
Advertising value is based on the notion that advertising and marketing messages are exchanged between advertisers and clients. According to Ducoffe et al. (1996) and Rubin (2002), informativeness refers to the capability of advertisement to efficiently bring and convey facts to the expected consumers. Entertainment value refers to the extent of consumers' pleasure when exposed to the advertisement (Mahatmavidya & Yasa, 2020). The informativeness and entertainment elements of advertising are crucial to the advertising effectiveness (Aaker, 1992). Besides its positive values, an advertisement may also be irritating as it may use annoying, offending, or insulting contents, or that appear to be overly manipulative (Ducoffe et al., 1996).
The sender's ability to logically attract the customers' response by allowing the consumers to cognitively analyze the information and messages offered by the sender is related to informativeness. (Pavlou et al., 2007). The informativeness of an advertisement will enhance the advertising effectiveness (Haida & Rahim, 2015). According to Chiang et al. (2017), the information and presentation conveyed in an advertisement may influence a customers' attitude toward the advertisement itself. The level of informativeness in the social media advertising leads to a favorable buying behavior which in turn encourages customers to purchase the product. Consumer engagement with a brand can be reinforced through enjoyment, that eventually could lead to the intent of buying a product (Dessart et al., 2015). Customers who perceive an advertisement as informative and pleasing are more likely to engage with it and hold positive emotions toward the advertisement (Ünal et al., 2011). The relationships are presented as follows: H1: Informative social media advertising enhances customer engagement H2: Informative social media advertising increases purchase intention H3: Entertaining social media advertising increases customer engagement. H4: Entertaining social media advertising increases purchase intention. Carr and Brackett, (2001) define credibility as the content and source used in the advertisement which in turn affects customers' trust. They argue that customers look for credibility when they evaluate advertisements and form opinions about them. Aktan et al. (2016) argues that a credible advertisement increases the overall advertising value, which eventually enhances its effectiveness in shaping customer attitudes and behaviors of the product. Even though the company already provides credible information within the advertisement, it may not be effective in stimulating purchase intentions within customers if it fails to engage with the customer with the brand and build customer trust (Chiang et al., 2017). Customers tend to give more attention and positive responses to the advertisement that can be trusted (Kim & Han, 2014). Furthermore, Sheeraz et al. (2012) found that brand credibility has a positive and strong effect on purchase intentions. Referring to these statements, the following hypotheses are proposed: H5: Credible social media advertising increases customer engagement. H6: Credible social media advertising increases purchase intention.
Interactivity refers to the brand's ability to create a positive interaction with customers through which customers may experience sympathetic resonance toward the product usage experience or others' thoughts of the brand (Song et al., 2018). For reference, Social media allows individuals to create connections with others who share similar characteristics, interests, or preferences with them. This connection enables them to influence each other (Chiang et al. 2017). Interactive social media brand pages may affect consumers' perceptions of a brand (Cheung et al., 2020) by providing a hyperlink to the reputable internet site and inspiring customers to share and disseminate brand associated records to decorate interactivity (Manthiou et al., 2014). Sellers may also encourage consumer participation through consumer submission of their stories, posting of comments, and subscription to the brand web page (Dessart et al., 2015). An interactive social media advertisement may increase customers' willingness to comment on social media, share the content to others, and engage with the brand (Chiang et al., Social media advertising improves customer engagement since it may inform, entertain, and interact with users. Social media also enables social ties with other users, which increases the effectiveness of the company's social media marketing (Cheung et al., 2011). A higher level of engagement between the customers and the brand encourages customers to convey and share brand-related information to other people that strengthens the brands image (Brodie, 2013;Hanna et al., 2011), attracts other customers' attention, and increases customer ability to recall the brand in their minds, which thereby enhances brand awareness (Langaro et al., 2018). Because of its capability to impact customers' brand choices, customer engagement with the brand is an essential aspect in the brand-building strategy. Effective and engaging advertising may encourage customers to purchase the products advertised or discussed in social media (Qamar, 2013).
Customer engagement is one of the key factors in a marketing output that may attract customers and lead them to take part in the community activities. The more active and positive the community activity is, the more likely the customer is to highly prefer the brand (Chiang et al., 2017). A greater customer engagement may lead to higher purchase intention and loyalty by customers (Rahmawati & Aji, 2015) which finally brings success to a brand (So et al., 2012). The last hypothesis in this study is: H9: Customer engagement increases purchase intention

METHOD
A survey was designed to understand Indonesian consumers' purchase intention of sneaker brands. This research uses purposive sampling to determine the sample of the study which requires a certain criterion so that the sample is in accordance with the research objectives. To ensure their ability to provide objective answers in the questionnaire, the subject should have bought sneakers in the last one year, followed by the official account of their favorite sneaker brand, and proof of having followed the advertising content on the official account of their favorite sneaker brand in the last 6 months. A closed-ended online questionnaire was prepared in Google Form and the link was shared throughout social media applications, such as Whatsapp, LINE, and Instagram. The survey was conducted in mid-October to mid-November. In total, 352 people responded to the survey. After eliminating data from respondents who did not match the criteria and cleaning the inconsistencies, 314 eligible responses were used in this analysis.
We borrowed measurement items from literature. The informativeness, credibility, and entertainment advertising values were measured by 12 items adopted from Choi and Rifon (2002), each value was represented by 4 items. Interactivity was measured by 4 items from Mahatmavidya and Yasa (2020). Customer engagement was measured from Zhang et al., (2017). Purchase intention was measured from Zhang (2010). All items were measured using a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree).
This research used PLS-SEM to test the hypotheses due to several reasons. First, this study was speculative in nature as it intends to predict the key factors that influence customer purchase intention. Second, some variables have less than four valid or reliable factors to count them with, which were required in the CB-SEM. The test used SmartPLS 3.0 software.

Results
As shown in Table 1, the proportion of male respondents was slightly greater than females. More than 79 percent of respondents were young, between the age of 15-24. Around 31% of respondents were active followers of the official brand's Instagram account by seeing the contents of their favorite sneakers brand every time there is a new post or at least once a week. Of all active followers of the sneaker brands' account, many of them were paying attention to the contents of their favorite sneakers brand's official social media account at least one month ago.  Table 2 shows that some items were excluded from the analysis due to validity issues. The remaining 26 items had outer loadings between 0.638 and 0.864, and AVE above 0.5. These items had composite reliability between 0.827 and 0.909, and Cronbach's alpha between 0.582 and 0.887. As shown in Table 3, the discriminant validity requirement was fulfilled because the square root of average variance extracted (AVE) for every construct was greater than its correlation with other constructs in the model. Based on the R 2 , informative, credible, entertainment, and interactive advertising values might explain the variability of customer engagement by 43.8 percent. Two out of four dimensions of social media advertising value: informative (β = 0.077, p-value = 0.117) and credible (β = 0.056, p-value = 0.169) had insignificant effect on customer engagement, so H1 and H5 were not supported. The remaining two dimensions: entertaining (β = 0.321, p-value = 0.000) and interactive (β = 0.334, p-value = 0.000) had significant positive effect on customer engagement, which gave support to H3 and H7.

Discussion
Contrary to the theory, this study finds informative advertising does not lead to higher customer engagement and purchase intention. It does not support a study by Hermawan (2018) that finds informative advertising will effectively increase the customer engagement and Rotzoll and Haefner (1977) who reveals the informative advertising may guide customers in making purchasing decisions. It seems that young respondents are not satisfied only with informative advertising. They are technology savvy as they obtain information from various sources, not only from the official brand social media. Hence, informative content in the advertising is not strong enough to build customer engagement and willingness to buy the sneaker brands, which is similar to Chiang et al.'s (2017) study.
Unlike Ünal et al. (2011Ünal et al. ( ), Eisenman et al. (2014, and Chiang et al. (2017) who found that customer's perception toward credible advertising content and source might result in positive interactions with the brand and greater willingness to buy, this research fails to prove such relationships. Spangenberg and MacLachlan (2005) suggest that when people are suspicious about a message, they are not motivated to absorb or believe it. They do not trust the posts and describe the post creators as "dodgy". As anyone may publish anything in social media, they do not think social media is a reliable platform for this kind of information.
These findings show that entertaining social media advertising value has a significant positive effect on purchase intention through customer engagement. Dessart et al. (2015) argue that entertaining online advertising and marketing can construct intimate feelings with the brand and strengthen purchase intention. Dolan et al. (2015) mentioned that entertaining advertising is likely to generate active engagement behavior. It leads the respondents to comment on it, share their thoughts about the brand, re-post the advertisement, and participate in the event held by the brand, even create user-generated content. As they become emotionally engaged with the brand, they tend to have higher preference toward the brand, which eventually affects their willingness to buy. This finding is similar to Ji et al. (2021) about the effect of customer engagement with the correlation of entertaining advertising and purchase intention.
While entertaining online advertising value has an indirect effect on purchase intention, interactive value may directly affect purchase intention and indirectly through customer engagement. Similar to this research, Diga and Kelleher (2009) found a significant positive effect of interactivity and purchase intention. Social media enables the users to interact with the brand and other users that are presented through their ability to comment on the advertisement, share their ideas or experiences when using the brand, or create content for the brand. The ability of the brand to create a positive interaction through which customers may experience sympathetic resonance toward the product usage experience or others' thoughts of the brand results in active engagement behavior as also found by Dolan et al. (2015) and Chiang et al. (2017).
This study finds a significant positive effect of customer engagement on purchase intention, which supports Brodie et al. (2013) who found consumers may influence value-in-exchange and value-in-use of the product by sharing their personal experiences to influence others and advocate the brand. Due to the majority of respondents being youngsters, this finding confirms Matthews et al. (2021) who discovered that the potential of entrepreneurs in developing advertising strategies that are specially targeted to the unique orientation, identities, and choices of the Sneakerhead network will trigger better buy goals on the young customers.

CONCLUSION
This study gives better understanding and explanation of the relationship between online advertising value such as informativeness, credibility, entertainment, and interactivity with customer engagement and customer purchase intention in the sneaker context. Furthermore, this study adds to the existing literature on the mediating effect of customer engagement in the relationship between social media advertising value and purchase intention. While there are few studies that look into the effects of social media advertising value and customer engagement toward customer purchase intention (Chiang et al., 2017), this study confirms the ability of customer engagement to mediate the relationship between several elements of advertising value and purchase intention. Among four social media advertising values, entertaining and interactive advertisement are the only compelling elements to shape customer attitudes and behavior toward sneakers brands. While interactivity may affect the purchase intention either directly or indirectly through customer engagement, the entertainment advertising value can affect purchase intention only through customer engagement.
When a brand can maximize the entertainment and interactivity values through its advertisement, it can foster customer engagement that eventually influences customer purchase intentions. The entertainment value of the social media advertisement may be maximized in the form of attractive captions, content related to the customer segment, and authentic photos or videos. The interactivity value of social media advertisements may be increased by conducting Q&A sessions, providing product giveaways, and reposting the customers' contents that present their review or photos of the products. As customer engagement has a substantial impact on purchase intentions, the company can emphasize entertaining content in its advertisement, ask the followers to participate in surveys, promotions, giveaways, and encourage them to create their own generated content about the brand. These efforts will increase customer contributions by giving likes, comments, and sharing the posts. This form of engagement provides valuable and free feedback instantly.
Even though this study discusses four social media advertising values that consist of informativeness, credibility, entertainment, and interactivity, it does not include other advertising values such as irritation (Ducoffe et al., 1996) and personalization / customization (Alalwan, 2018;Arora & Agarwal, 2019;Cheung et al., 2020). Future research may include these social media advertising values to obtain a more comprehensive understanding on the effect of advertising value on purchase intention. Also, future research may add other variables such as overall advertising value, attitude toward social media advertising, and shopping