(By: Mohammad Sofyan Hadi, Sarah Nuraini Maghfiroh)

The digital revolution in economic activity has driven a shift in consumer behavior, shifting from brick-and-mortar stores to online shopping. While this shift has led to the closure of several traditional markets, according to katadata.co.id, online purchasing interest is projected to continue to increase through 2022 , with an estimated 43.9 million shoppers, representing 15.7% of Indonesia's population.

Based on the results of the DNA ecosystem survey (Device, Network, Apps) in 2018, internet users based on age were dominated by those aged 19 to 34 years at 49.52%, second place was 35-54 years at 29.55% and teenagers aged 13-18 years at 16.68% while based on work, it was dominated by students or college students. The average internet user in Indonesia accesses the internet for 8 hours 51 minutes a day. according to wearesocial, internet users in Indonesia spend most of their time accessing social media, one of which is Instagram.

Instagram users from all over the world at the beginning of July 2011 were 10 million, then in April 2012 it increased to 30 million users, in the following year, at the end of 2013 Instagram users rose to 80 million users, Instagram users continued to increase until June 2018 to 1 billion users. In Indonesia in 2018 Instagram users reached 55 million people and ranked third in the world, after the United States and Brazil.

The increasing number of Instagram users has led to the emergence of product marketing methods through Instagram, one of which is through Instagram users with many followers or known as celebgrams, the product marketing method through celebgrams is usually called Celebrityendorsement , according to Shimp (2003:28) Celebrityendorsement is an advertising supporter or figure (actor, entertainer, or athlete) who is known to the public because of his achievements in fields that are different from the product class being supported.

The rate for celebrity endorsement depends on the number of followers and the type of post desired, for example, the rate for celebrity Awkarin starts from 1.5 million to 15 million depending on the type of post desired , then RiaRicis ranges from 5 to 8 million, in addition to the rate for posting on Ayu Tingting's Instagram feed is around 50 million . Then how much influence does the endorsement carried out by celebrity Instagram affect consumer purchasing interest in consuming a promoted product?

To examine how big the influence of endorsements made by celebrity Instagrammers is on consumer purchasing interest, we will use the multiple regression analysis method, namely an analysis used to predict the condition (rise and fall) of the dependent variable if 2 or more independent variables as predictor factors are manipulated (their value is increased or decreased), the regression equation is

Y=b ₀ +b ₁ X ₁ +b ₂ X ₂ +b _n X _n +e

Where Y is the dependent variable and X is the independent variable or free variable.

For the first case, the author used a research sample from the Instagram account @Joyagh, where the population of followers as of April 23, 2019 was 636,000. The sampling technique used probability sampling , which provides equal opportunities for predetermined samples, while the method used was simple random sampling , which is a method of taking samples from population members using a random system, where the research sample consisted of 100 respondents who filled out the questionnaire online with the help of the online survey monkey with an error rate or error tolerance of 10%. The variables used were independent variables namely visibility (X1) , credibility (X2) , attractiveness (X3) , product match up (X4) and power ( X5 ) .

Visibility According to Rossiter and Percy (1997: 294) is how popular or famous a model or celebrity is, Visibility in celebgram itself means how popular the celebgram is that can be shown through his/her Instagram followers . Credibility concerns consumer perceptions of the celebgram in achieving or not the message objectives of the advertisement made by the celebgram , according to Rossiter and Percy (1997: 294) Credibility has 2 characteristics, namely expertise and trust where the celebgram must have expertise, and trust in conveying his/her message , and the objectivity of the celebgram in instilling consumer confidence to consume a product. Attractiveness is the nature of celebrities that becomes an attraction through the level of similarity and the level of consumer preference for the product being promoted and according to Mowen and Minor (2002: 405) attractiveness refers to the self that is considered attractive to look at in relation to the concept of a particular group with physical attractiveness. An attractive person is perceived more positively and reflects the advertised brand better than someone with average attractiveness. Product match up is the match between the celebrity's personality and the product being promoted. Power according to Rossiter and Percy (1997:297) is the ability to influence and follow what is displayed by the communicator, power in celebrity is the celebrity's power to influence or persuade. While variable or variable Y is consumer purchasing interest in the product promoted by the celebrity . The calculations carried out obtained the following results:

• Based on the results of the survey and simultaneous test (F Test) produced a _calculated = 160.407 with a probability of 0.000. The test results show the probability of _calculated < level of significance (a = 5%). This means that there is a significant influence simultaneously (together) by the variables of visibility, credibility , attractiveness, product match up, and power on consumer purchasing interest in products promoted by celebrity grams .
• In partial testing using the t test, it states that each calculated probability < level of significance (a=5%), then the influence is significant individually visibility on purchase interest with t _count = 4.628 with probability 0.000 and assumption of other independent variables constant , credibility on purchase interest with t _count = 3.047 with probability 0.003 and assumption of other independent variables constant , attractiveness on purchase interest with t _count = 2.475 with probability 0.015 and assumption of other independent variables constant , product match up on purchase interest with t _count = 6.721 with probability 0.000 and assumption of other independent variables constant , and power (X5 ) on purchase interest with t _count = 2.695 with probability 0.008 and assumption of other independent variables constant.
• The magnitude of the contribution of visibility, credibility , attractiveness, product match-up, and power to purchase interest can be seen through the coefficient of determination ( adjusted R2 ⁾ , which is 0.863 or 86.3%. This means that the diversity of purchase interest can be explained by the variables visibility, credibility , attractiveness, product match-up, and power by 86.3%, while the remaining 13.7% is the contribution of other variables not discussed in this study.

Meanwhile, for the second case, the author used a research sample of 100 respondents aged 18 to over 50 years with a data collection method in the form of a quota sampling method taken based on 5 major cities in Indonesia (Jakarta, Medan, Bandung, Makassar, and Surabaya) which was carried out through an online questionnaire with an error tolerance of 10% (Aditya Halim Perdana Kusuma Putra and team, 2018), there are 3 influential independent variables, namely trustworthy (X1) , attractive (X2) , and expertise (X3) . Trustworthy means a celebrity must be honest in conveying advertising messages and be consistent and the content of the advertising message can be trusted. Attractive means a celebrity must be in accordance with the product to be promoted, the product being promoted is far from negative news, and the celebrity has an attractive appearance. Expertise means knowing and mastering the product being promoted, having expertise and knowledge of the product being promoted and must be trusted, Engel et. al (1995: 87) said that the level of knowledge or expertise of the source is the main determinant of credibility. Meanwhile, the dependent variable, or Y variable, is consumer purchasing interest in products promoted by celebrity Instagrammers . The calculations yielded the following results:

• the trustworthy, attractive, and expertise variables was obtained _{a calculated} F of 32.433 with a probability of 0.000. The test results indicate a _calculated < level of significance (a=5%). This means that there is a significant simultaneous (together) influence by the trustworthy, attractive, and expertise on consumer purchasing interest in products promoted by celebrity grams .
• In partial testing using the t test, it states that each calculated probability < level of significance (a = 5%), then there is a significant influence individually trustworthy on purchasing interest with t _count = 3.265 with a probability of 0.002 and the assumption that other independent variables are constant , attractive on purchasing interest with t _count = 3.962 with a probability of 0.009 and the assumption that other independent variables are constant , and expertise on purchasing interest with t _count = 3.092 with a probability of 0.008 and the assumption that other independent variables are constant.
• The magnitude of the contribution of trustworthy, attractive, and expertise to purchase intention can be seen through the coefficient of determination ( adjusted R2 ⁾ , which is 0.538 or 53.8%. This means that the diversity of purchase intention can be explained by the variables trustworthy, attractive, and expertise by 53.8%, while the remaining 46.2% is the contribution of other variables not discussed in this study.

We can observe from the two cases above, the results of the study on the first case that Instagram in its use aimed at introducing businesses through endorsements made by celebgrams have several characteristics to attract consumer purchasing power including visibility , credibility, attractiveness , product match up and power , where partial testing (one by one independent variable against the dependent variable, assuming other independent variables are considered constant), and simultaneous or joint testing have a significant effect on consumer purchasing power. Likewise in the second case, endorsements made by celebgrams to attract consumer purchasing power use the characteristics of trustworthy , attractive , and expertise, where partial testing (one by one independent variable against the dependent variable, assuming other independent variables are considered constant) and simultaneous or joint testing have a significant effect on consumer purchasing power.

We can conclude that the product promotion strategy by endorsing celebrity Instagram is a promotional strategy that is currently trending, from the two cases above, the two research samples, although different in the variables or characteristics of the assessment and different in the data collection or samples used, that the endorsement carried out by a celebrity Instagram will influence the consumer's purchasing interest, where consumers will see several factors that influence their purchasing interest from the endorsement carried out by the celebrity Instagram.

Reference

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