THE EFFECT OF ENDORSERS AND SOCIAL MEDIA ADVERTISING ON CONSUMER PURCHASE DECISIONS OF INSTAGRAM SOCIAL MEDIA USERS WITH BRAND AWARENESS AS A MEDIATING VARIABLE

This study aims to examine the effect of endorsers and social media advertising on consumer purchase decisions of Instagram social media users with brand awareness as a mediating variable. The research sample used in this study was 150 samples with a purposive sampling technique. The data used was primary data obtained by distributing questionnaires to Instagram social media users. The data analysis technique used was SEM with Smart PLS 3 software. The results show that social media advertising has a significant effect on brand awareness, endorsers have no effect on brand awareness, brand awareness has a significant effect on consumer purchasedecisions, social media advertising has a significant effect on consumer purchase decisions, endorsers have a significant effect on consumer purchase decisions, social media advertising has no effect on consumer purchase decisions through brand awareness, and endorsers have no effect on consumer purchase decisions through brand awareness.


INTRODUCTION
An endorser can be defined as a person involved in communicating messages, can directly or indirectly use their fame to promote a product and service (Setiawan & Rabuani, 2019). In this case, it will make consumers feel more confident in the product they want to buy. Indirectly, endorsers also influence consumer purchase decisions in the desired product. In advertisements shown to the public, many companies use endorsers to popularize their products. In addition to aiming to increase consumer confidence, the company also intends to make its products more widely known to the public.
These days, many people access and see advertisements through social media. Previously, many people saw advertisements from print media such as newspapers/magazines or television. However, from time to time, print media or television has begun to be abandoned, and now, many people access advertisements on social media like Instagram. In accessing advertisements, a consumer tends to look for advertisements that he is interested in. Therefore, companies must make attractive advertisements to attract more consumers. Moreover, consumers also choose and consider brands in the advertisements shown. Brand awareness is the consumer's ability to recognize or remember that a brand belongs to a specific product category (Setiawan & Rabuani, 2019). In the sense that it is quite widely known by consumers, strong brand awareness will make consumers feel more confident in determining purchase decisions for the desired product. The object of this study is Instagram because, recently, many people use that social media, which will increase opportunities and almost everyone in Indonesia uses Instagram social media. People who use Instagram can share images, which their followers can see. In addition, some use Instagram as a medium for selling products or promotions so that more users or consumers know the products.
Instagram ads will appear in the home column. If we scroll continuously down, we will see one or more ads. In Instagram social media, companies generally communicate ads, and to notice it as an advertisement; consumers will see "sponsored" writing below a company's account name. Indirectly it will attract consumers to see the products offered, and there is the possibility of consumers to look further into the account or make a purchase of the product. Thus, it will add and expand the market in the future.
There are other advertising methods in Instagram social media ads, such as products in specific fields promoted by endorsers like movie stars or other parties. In general, an endorser has many followers on his Instagram account, allowing the product to attract, be seen, and bought by many people. There are other advertising methods on Instagram, such as the paid promotion method that is an advertising system in which both parties (service sellers and buyers) have a specific agreement on product advertising so that more people know and see the product. Service sellers charge certain fees for the products they want to advertise.
The more buyer requests for the product one wants to advertise, the higher the paid promotion rate will be. Many people promote their products through Instagram, where nowadays, it does not take much time and effort to buy something. There are several examples of Instagram ads, such as selling products in the form of goods or services. As a seller, it is essential to devote more efforts to make a product more well known to people, and the existence of social media is expected to ease sellers or advertisers to communicate with buyers. Sellers must maintain the quality of their products to make a consumer loyal to the products they sell.

Endorser
Endorser refers to an individual involved in product promotion, such as an artist, an athlete, or an individual with fairly high fame. For example, a public figure who is known for his skills or fame. They use their fame and popularity to promote a product to make the product better known to many people (Setiawan & Rabuani, 2019). Companies usually choose several public figures, such as television and movie stars, and people with big names, or other achievements that are widely used in magazine, radio, spot, and television advertisements to strengthen a product name and consumer confidence (Setiawan & Rabuani, 2019).
Endorser credibility is considered essential because the increasing interest in the endorser will increase the product users' trust. Indeed, an endorser should always keep his name in order to be known and well known by his followers. Trustworthiness is also something that every endorser can be proud of. The effectiveness of a message also depends on the attractiveness of each endorser, where each endorser will make the advertised product as attractive as possible to make the product more trusted by the public.

Social Media Ads
Advertising is a medium that communicates a particular product message or information, generally done for a fee, and aims to invite consumers. It is expected to influence readers or viewers so that they can purchase the product. In general, advertising is associated with promotions to make consumers more interested in buying the desired product. It is also hoped that the advertising will increase the company's sales in the future. With the ads, it is hoped that every consumer who sees the ads will be interested, and there is the possibility of people telling others about the advertised product; thereby, it will also expand the ad network. The more people know the advertisement, the more prosperous the company will be because they can indirectly be promoted and popularized so that many people know and are interested in the advertised product. According to Kotler andKeller (2016, in Putra &Suryana, 2018), the objectives of advertising are as follows: First, Informative advertising. It is intended to inform the public of products and services, which aims to create brand awareness so that consumers can understand more and deeper about the advertised products. Second, Persuasive advertising. It aims to provide likes, preferences, beliefs, and purchases of products or services. Some persuasive advertisings are like comparative advertisings, which explicitly compare the attributes of two or more brands. Third, Reminder advertising. It aims to make consumers remember certain products to always make consumers have the desire to use the product and attract them to make repeat purchases. In this case, marketers try to get consumers to remember the ads, so that it appears more quickly in the minds of consumers. Finally, Reinforcement advertising. It aims to convince consumers that they have made the right choice and the right decision. For example, in automotive industry advertisements (especially cars), reinforcement advertising shows satisfied consumers with their new car's features.
There are other advertising options on social media, one of which is Instagram social media. Today's Instagram social media has a lot of fans and users. Some use their Instagram social media a medium to do business. Therefore, this study aims to examine how influential Instagram ads are on consumer purchase decisions.
The advertising method can be done using various features on Instagram, such as Instagram stories, posts, or the paid promotion method, where students mostly do this method. Paid promotion is an advertising system in which both parties (service sellers and buyers) agree on certain rules. Paid promotion can be done through Instagram stories, where this feature enables users to upload photos or short videos that automatically disappear within 24 hours.

Consumer Purchase Decisions
In determining a purchase decision, consumers consider several things, such as the influence of other people and/or advertising, a strong brand image, and a low product price. According to Kotler and Armstrong (2014), in Hasbi, 2017), a purchase decision is one of the decision-making process stages where consumers actually make purchases of the desired products, product attributes with good quality, appropriate target markets, and the right product prices. Each individual may have a different perspective in doing something or certain things. This perspective influences consumers in making decisions because consumers must think about certain things before making a purchase decision, as explained above. Purchase decision is a psychological process experienced by consumers starting from the stage of attention or consumer knowledge of the products or services offered, then the stage of interest and further curiosity of the products or services, then the stage of interest, and concludes with making a decision to buy or not (Solomon, 2014;in Setiawan & Rabuani, 2019). Consumers are more interested in making purchases if the quality of the products offered is guaranteed, or because of low prices and product promotions that are enough to attract people's attention, determining future purchase decisions. While things that can influence consumer purchase decisions are the influence of the surrounding environment that will build consumer interest in making purchases.
In this present study, consumer purchase decisions are more directed to consumers who use or are active in Instagram social media. In social media, purchase decisions are formed through consumer interactions with the online environment. Understanding the online decision-making process can increase our knowledge of online consumers more broadly. The decision-making process can be explored by developing new behavioral models. Therefore, modeling the entire buying decision-making process is needed.

Brand Awareness
Brand awareness is often considered a prerequisite for consumer purchase decisions because it is a major factor, including brands, in purchase decisions (Keller et al., 2011;in Setiawan & Rabuani, 2019). Brands are developed not only through advertising but also concerning consumer trust over time. Brands are introduced by implementing strategies and the right value -creativity in determining segmentation and strategy, and developing strong differentiation; (Keller et al., 2011;in Setiawan & Rabuani, 2019).
Brand awareness can be defined as the extent to which consumers can know and understand existing brands. Companies can build brand awareness with things that can attract consumers, such as promotions or advertisements that can attract consumers' attention so they can make purchases of these products. Advertisements help increase brand awareness. These are necessary conditions for affective (i.e., brand preference) and behavioral advertising effects (i.e., purchase requisitions).

Hypothesis Development
It implies that marketers in making advertisements will point to certain brands or brands to get a positive reaction from consumers. This study supports previous research conducted by Setiawan & Rabuani, (2019) stating that advertising has a significant positive effect on brand awareness. H1: Social media advertising has an effect on consumers' brand awareness of Instagram users.
These days, many endorsers are used for advertising brands to consumers. Setiawan and Rabuani's (2019) study reveals that endorsers have a significant positive effect on brand awareness. H2: Endorsers have an effect on consumers' brand awareness of Instagram users.
Consumer knowledge of the brand/brand awareness refers to the ability of prospective buyers to know and recognize, or recall, and ultimately be able to determine purchase decisions. Setiawan and Rabuani's (2019) study reveals that brand awareness has a significant positive effect on purchase decisions. H3: Brand awareness has an effect on consumer purchase decisions of Instagram Users.
Advertising is any paid form of promotion from an identified sponsor or source that influences consumer purchase decisions. Setiawan and Rabuani's (2019) study reveals that advertising has a significant positive effect on purchase decisions. H4: Social media advertising has an effect on the consumer purchase decisions of Instagram Users. Endorsers are individuals who use their popularity to promote a product. This is done in order to attract consumers to make purchases of the product. Setiawan and Rabuani's (2019) study reveals that endorsers have a positive effect on brand awareness.
H5: Endorsers have an effect on Consumer Purchase Decisions as Users on Instagram.
Advertising will attract consumers in determining purchase decisions. In this case, consumers will consider the brand of the product to be purchased. Setiawan and Rabuani's (2019) study reveals that advertising has a direct effect on purchase decisions through brand awareness. H6: Social media advertising has an effect on consumer purchase decisions of Instagram users with brand awareness as a mediating variable.
Endorsement is a promotion that utilizes celebrities' popularity to attract consumers. Setiawan and Rabuani's (2019) study reveals that endorsers have a direct effect on consumer purchase decisions through brand awareness. H7: Endorsers have an effect on consumer purchase decisions of Instagram users with brand awareness as a mediating variable.
The research model is as follows:

RESEARCH METHODS
The present study is causal research. According to Sugiyono (2016:37, in Winata, 2019, causal research investigates cause and relationships. In this study, the researchers examined the effect of endorsers and social media advertising on consumer purchase decisions of Instagram social media users with brand awareness as a mediating variable.

Variable and Operational Definition Endorsers variable (act as independent variable)
Endorsers can be defined as consumers' ability to get information about product promotions on Instagram social media by involving people who use their fame to promote a product and service. According to Sääksjärvi, et al. (2016, in Setiawan andRabuani, 2019), there are several sources of indicators in the endorser as follows: 1. Attractive face of the endorser, meaning that the endorser's face is important in carrying out certain activities such as product promotion. 2. Fame of the endorser, is the extent to which the public knows the endorser. 3. Attractive appearance of the endorser, meaning that the endorser's appearance can attract consumers to use a product. 4. An endorser that can attract consumers' attention, meaning that the endorser can make consumers know more about the product. 5. Endorsers who can influence consumer thinking through their style, or lifestyle, or something else. 6. Experience of the endorser is the endorser experience in the entertainment world.
Social media advertising variable (act as independent variable) Advertising refers to the consumer ability to obtain any information through certain media regarding certain product. This present study examines Instagram social media advertising. According to Chen andChang, 2003, in Setiawan andRabuani, 2019), there are several sources of indicators in social media advertising as follows: 1. As a medium of information, it can be in the form of goods, services, or product promotion to consumers. 2. Advertising that can persuade consumers to purchase a product. 3. Advertising attractiveness to encourage consumers to use applications, products, or platforms. 4. Create a desire for consumers to use applications, products, and platforms. 5. Interesting message in the ads.

Consumer purchase decisions variable (act as dependent variable)
Consumer purchase decisions can be defined as the consumer's ability to determine two or more alternative behaviors and choose one of them on Instagram social media. According to Solomon (2014, in Setiawan andRabuani, 2019), there are several sources of indicators in consumer purchase decisions as follows: 1. Alternative choices in determining purchase decisions of certain applications or platforms. 2. Reuse of alternative choices in determining purchase decisions. 3. Consumer satisfaction concerning the use of applications and platforms in determining purchase decisions. 4. Ease of use of applications and platforms in determining purchase decisions. 5. Recommendations of applications and platforms to other consumers.

Brand awareness variable (act as mediating variable)
Brand awareness can be defined as the consumer's ability to know or remember that a brand is part of a certain product category in Instagram social media. According to Keller et al. (2011, in Setiawan andRabuani, 2019), there are several sources of indicators in Brand Awareness as follows: 1. Brand recognition, consumers can understand and perceive the brand. 2. Top of mind, the first brand that appears to customer's mind. 3. Unaware of the brand, consumers feel doubtful and unsure of a brand. 4. Consumers who frequently make purchases on the application or platform.

Population and Sample
The population of this study was students in Surabaya, especially those who have an Instagram account. This study used a non-probability sampling technique. According to Sugiyono (2016: 84, in Dendy, 2020), non-probability sampling refers to a sampling technique where not all population members have an equal opportunity to be selected as a sample. The type of non-probability sampling used was a purposive sampling technique. According to Sugiyono (2016:85, in Dendy, 2020, purposive sampling is a data sampling technique based on specific considerations. The targeted sample of this study were respondents who have an Instagram account, at least 16 years old, and are domiciled in Surabaya. The number of samples was 150 students with the characteristics of 84 were males (56%), and 66 were females (44%). Moreover, 84 respondents were at the age group of 17-21 years (56%), 44 respondents were 22-25 years (29.3%), 19 respondents were >25 years old (12.7%), and 3 respondents were under 17 years old (2%). While concerning the length of use of Instagram, 62 respondents use Instagram for more than 5 years (41.3%), 46 respondents use Instagram for 1-3 years (30.7%), 46 respondents for 4-5 years (26.7%), and 2 respondents were less than 1 year (1.3%).
The type of data used in this study was quantitative data with primary data as a data source. The data collection method used was a survey using Google Form to collect data from a questionnaire.

RESULTS & DISCUSSION
The endorser variable was measured using 6 measurements. The total mean value of the Endorser variable is 3.984. The social media advertising variable was measured using 5 measurements. The total mean value of the social media advertising variable is 3.956. The consumer purchase decisions variable was measured using 7 measurements. The total mean value of the consumer purchase decision variable is 4.054. The brand awareness variable was measured using 4 measurements. The total mean value of the brand awareness variable is 4.223. The following is a table of descriptive statistics of variables: There were two validity testing, namely, convergent and discriminant validity, carried out in this study. Convergent validity is aimed at the degree of conformity between the attributes of the measurement results and the theoretical concepts that explain the existence of the attributes of these variables. Convergent validity includes the Average Variance Extracted (AVE) value. The expected AVE value is more than 0.5, which indicates that more than half of the constructs explain the indicators (Ghozali, 2015 in Salsabila A., 2019). The following table are the results of the convergent validity test: Discriminant validity is an additional concept which implies that conceptually different concepts must show adequate differences (Hidayat, 2018). Discriminant validity is used to prove that the points contained in each latent variable are not messed up by the respondents who answer each of the questionnaire points based on the statements of the other variables. The following table are the results of the discriminant validity test: The reliability test in this study was carried out by measuring the reliability value of Cronbach Alpha that has been determined, namely > 0.6 and for Composite Reliability > 0.7. The following table are the results of the composite reliability test:  The following are the results of the Cronbach Alpha Reliability Test: The structural model fit test refers to a test that aims to examine the relationship between the hypothesized variables. The results of the structural model fit test can be seen in the following R-square table: Endorser, social media advertising, and consumer purchase decisions variables can explain the brand awareness variable as much as 20.4%. Meanwhile, the remaining 79.6% of the brand awareness variable is explained by variables not included in this study. The consumer purchase decision variable is 0.815, thus implying that endorser, social media advertising, and brand awareness variables can explain the consumer purchase decision variable as much as 81.5%. Meanwhile, the remaining 18.5% of the consumer purchase decision variable is explained by variables not included in this study.
The mediating variable test in this study used the Bootstrapping method. Bootstrapping is a non-parametric approach that does not assume the form of variable distribution and can be applied to a small number of samples (Ghozali, 2005, in Darsono, 2017. The results of the bootstrapping test are as follows: Hypothesis testing aims to determine the results of the significance between variables using the SEM (Structural Equation Modeling) method with the SmartPLS 3 program. According to Ghozali andFuad (2005:40 in Dendy, 2020), hypothesis testing criteria are said to be significant if each parameter estimate has a t-value is greater than 1.96 (t-value>1.96). The results of hypothesis testing can be described as follows: The results of hypothesis testing are as follows: Hypothesis 1, The social media advertising variable on brand awareness has a t-value of 2.375, indicating a value of more than 1.96. The influence coefficient between the two variables is 0.580. This result indicates that the two variables have a significant effect; therefore, H1 is accepted. Hypothesis 2, The endorsers variable on brand awareness has a t-value of 0.533, indicating a value that is less than 1.96. The influence coefficient between the two variables is -0.136. This result indicates that the two variables have no significant effect; therefore, H2 is rejected. Hypothesis 3, The brand awareness variable on consumer purchase decisions has a t-value of 4.376, indicating a value that is more than 1.96. The influence coefficient between the two variables is 0.184. This result indicates that the two have a significant effect; therefore, H3 is accepted. Hypothesis 4, The social media advertising variable on consumer purchase decisions has a t-value of 4.071, indicating a value of more than 1.96. The influence coefficient between the two variables is 0.478. This result indicates that the two variables have a significant effect; therefore, H4 is accepted. Hypothesis 5, The endorsers variable on consumer purchase decisions has a t-value of 3.067, indicating a value of less than 1.96. The influence coefficient between the two variables is 0.339. This result indicates that the two variables have a significant effect; therefore, H5 is accepted. Hypothesis 6, The social media advertising variable on consumer purchase decisions through brand awareness has a t-value of 0.347, indicating a value of less than 1.96. The influence coefficient between the two variables is -0.042. This result indicates that the two variables have no significant effect; therefore, H6 is rejected. Hypothesis 7, The endorsers variable on consumer purchase decisions through brand awareness has a t-value of 0.435, indicating a value of less than 1.96. The influence coefficient between the two variables is 0.048. This result indicates that the two variables have no significant effect; therefore, H7 is rejected.
This study aims to examine the effect of endorsers and social media advertising on consumer purchase decisions of Instagram social media users with brand awareness as a mediating variable. Social media advertising has a significant positive effect on brand awareness. This proves that social media advertising that delivers interesting messages and information and attracts consumer attention can increase consumer knowledge of the brand (brand awareness) of Instagram social media users. Endorsers have no significant effect on brand awareness. This proves that an endorser's attractive face or appearance may not necessarily increase consumer knowledge of the brand (brand awareness) of Instagram social media users. Brand awareness has a significant positive effect on consumer purchase decisions. This proves that brand awareness built through logos or symbols can make consumers feel more confident in their purchase decisions. Social media advertising has a significant positive effect on consumer purchase decisions. This proves that social media advertising that delivers interesting messages and information and attracts consumer attention will increase consumer purchase decisions of Instagram social media users. Endorsers have a significant positive effect on consumer purchase decisions. This proves that an endorser's attractive face or appearance may not necessarily increase consumer purchase decisions of Instagram social media users. Social media advertising through brand awareness has an insignificant effect on consumer purchase decisions. This proves that social media advertising that delivers interesting information or messages through strong brand awareness does not necessarily increase consumer purchase decisions of Instagram social media users. Endorsers through brand awareness have no significant effect on consumer purchase decisions. This proves that an endorser's attractive face or appearance through strong brand awareness may not necessarily increase consumer purchase intention of Instagram social media users.

CONCLUSION
This study shows the results that (1) Social media advertising has a significant positive effect on brand awareness, (2) Endorsers have no significant effect on brand awareness, (3) Brand awareness has a significant positive effect on consumer purchase decisions, (4) Social media advertising has a significant effect positive on consumer purchase decisions, (5) Endorsers have a significant positive effect on consumer purchase decisions, (6) Purchase decisions do not mediate the relationship between social media advertising and brand awareness, and (7) Consumer purchase decisions do not mediate the relationship between endorsers and brand awareness.
The limitation of this study is that the number of respondents was only 150, all respondents domiciled in Surabaya, and they were less evenly distributed by age. The object of this study was also limited to only one social media, namely Instagram. It is hoped that future researchers can use Instagram social media more specifically and increase respondents, especially those who live outside Surabaya. Besides, the respondents in this study should have made purchases on Instagram social media, to avoid biased results. The criteria for the respondents needed in this study would be more appropriate related to.
Practical Recommendation, for the endorser management on Instagram social media, the increase of endorsers on Instagram social media can be done by introducing further to the public, for example, by giving certain characteristics of an endorser, such as a tagline spoken by an endorser, or an attractive appearance of an endorser, so that it can attract the attention of the people who see, and an endorser can have higher fame. For the Instagram social media advertising management, Instagram advertising can be increased by providing attractive advertising impressions to the public and providing other options such as product promotion, so that this will invite the public to be interested in product promotion and make the purchase. For consumer purchase decisions on Instagram social media management, consumer purchase decisions can be increased by providing easy access to purchases on Instagram social media and selling quality products at competitive prices to attract public attention to purchase the product. For brand awareness on Instagram social media management, brand awareness on Instagram social media can be increased by providing quality brand offers to the public. For brands that are still relatively new, the introduction can be done by promoting products and requesting consumers' testimonials for these products. If this gets a good response, then this can increase the brand name in the future.