MARKETING MIX AND REPURCHASE INTENTION OF CAFE INDUSTRY DURING COVID-19: A STATISTICAL AND DATA MINING ANALYSIS

The COVID-19 pandemic has hit the world and bring unprecedented changes to all industries, including the Micro Small Medium Entrepreneur (MSME) of coffee shop businesses. This study aimed to determine the effect of the marketing mix on customer satisfaction to increase repurchase intention in modern coffee outlets. In addition, statistical modeling, segmentation analysis, and variables weighting using Support Vector Machine were performed. Eventually, product, price, and place positively and significantly affect customer satisfaction, while the promotion does not. Customer satisfaction was found to increase the repurchase intention of the customers. The segmentation analysis and SVM weighting attributes support the product quality as crucial to the marketing mix. It is implied that marketers should devise a marketing approach differently to different clusters since each cluster has distinct characteristics.


INTRODUCTION
Along with the increasing mobility and modern lifestyle, especially in big cities in Indonesia, the growth of coffee shops has become relatively rapid. Not only drinking coffee, but usually, coffee shops are also a destination for some groups to carry out certain activities, such as meeting business partners, gathering with work friends, reunions, and even discussion areas for young people. The presence of cafes with accessible locations is very convenient to the public, both in malls and roadside, making competition between coffee shops incredibly tight (Kamaluddin, 2018). The development of the cafe business in Indonesia is currently multiplying. This number of cafes has sprung up, providing comfortable places with attractive interior designs and offering various facilities such as free Wi-Fi, friendly service, available menu variations, and even live music that attracts consumers' buying interest. The growth and the competition force every coffee shop to serve the best for its customers.
The COVID-19 pandemic also has a significant impact on the coffee beverage industry. The imposition of restrictions on the movement of people by the government resulted in a decrease in net income from coffee shop operations. The impacts experienced by the coffee beverage industry are related to the pandemic, including a decline in coffee prices and a shift in consumer buying interest (Kurniawan, 2020). Moreover, during this pandemic period, the coffee shop's problem is the instability of the number of visitors and income at the modern coffee shop in Medan. During the COVID-19 pandemic, there was a visitor decrease between 65%-85% and a decrease in turnover and profit between 65%-85% (Fathoni, 2020). According to Abdullah (2014), if the product offered exceeds consumers' expectations, the consumer will feel satisfied and repurchase the product. If the product provided is lower than consumer expectations, the consumer will feel disappointed and refuse to make repeat purchases against the product (Fadillah et al., 2020).
The urgency of this study is to answer the gap that research on consumer behavior intentions has shown mixed results. This study aims to elaborate on the role of the marketing mix in customer satisfaction and repurchase intention in the modern coffee shop in Medan. Since previous studies are mainly focused on statistical analysis, therefore to enrich the insights, a combination of statistical and data mining is proposed. This study provides an empirical research process and a practical managerial implication by utilizing statistical hypothesis testing and data mining analysis to provide insight into Micro Small Medium Entrepreneur (MSME).

Marketing Mix, Customer Satisfaction, and Repurchase Intention
One marketing strategy that companies can use to increase customer satisfaction and repurchase intentions is the marketing mix. The marketing mix consisting of product, price, location, and promotion is one of the marketing strategy tools. Its application requires an in-depth understanding of the company to combine these factors to maximize the success of the company's marketing activities (Utami & Firdaus, 2018).
The marketing mix is a marketing strategy that companies widely use. Companies that use this strategy must manage the marketing mix so that company performance can be optimal. The main objective of this strategy is to create customer satisfaction to induce repurchase intentions, as reinforced by the research (Kusuma & Suryani, 2017). Better management of the marketing mix will increase customer satisfaction, and customer satisfaction will increase repurchase intention.

Product and Customer Satisfaction
Products are any items that can be provided to the market to be noticed, purchased, used, or consumed that can satisfy your desires or needs (Tampubolon, 2021). The results of (Firmansyah & Mochklas, 2018) research show the product has a positive and significant effect on customer satisfaction. Kotler and Keller (2012: 150) argue that "after consumers buy these products, consumers can be satisfied or dissatisfied and engage in post-purchase behavior. Satisfied customers will probably return to buy the product, but dissatisfied customers will try other products produced by a different company" (Tejantara & Sukawati, 2018). Based on empirical and theory review, the first research hypothesis can be formulated: H1: Product has a positive effect on customer satisfaction

Place and Customer Satisfaction
Place or location is a specific point the company chooses to carry out all of its business activities, where the factor impacts its business strategies (Tampubolon, 2021). The results of (Wiranata, 2019) research show that price has a positive and significant effect on customer satisfaction. Likewise, (Setyandi & Satrio, 2018) research shows that the place affects the customers' satisfaction. Based on these researches, it can be proposed the second hypothesis as follow: H2: Place has a positive effect on customer satisfaction

Price and Customer Satisfaction
Price is given up or sacrificed to obtain a product or service (Halim et al., 2021). Furthermore, price is what a customer is willing to pay to receive a product or service (Madiistriyatno & Nurzaman, 2020). The results of (Wiranata, 2019) research show that price has a positive and significant effect on customer satisfaction. Therefore, the third hypothesis to be tested in the current study is: H3: Price has a positive effect on customer satisfaction

Promotion and Customer Satisfaction
Promotion is an activity that combines product excellence and appoints consumers to buy (Tampubolon, 2021). The results of (Firmansyah & Mochklas, 2018) research show the promotion has a positive and significant effect on customer satisfaction. Likewise, (Setyandi & Satrio, 2018) research shows that the promotion affects the customers' satisfaction. Based on this explanation, the hypothesis can states as follows: H4: Promotion has a positive effect on customer satisfaction

Customer Satisfaction and Repurchase Intention
Customer satisfaction is essential because it is a determinant of repeated purchase intentions. Repeat purchasing not only saves costs (rather than acquiring new customers) but will improve sales as well (Hussain, 2017). The results of (R. Arlanda, 2018) research show that customer satisfaction positively affects repurchase intention. Customer satisfaction also significantly influences customer intention to repurchase (Soebandhi et al., 2020). Based on this explanation, the hypothesis can states as follows: H5: Customer satisfaction has a positive effect on repurchase Intention

METHODOLOGY
This research was conducted in a modern coffee shop in Medan. In this study, all current coffee shop customers in Medan, such as Excelso, Starbucks, J.CO Donuts and Coffee, Maxx Coffee, Opal Coffee, and Coffeenatics. The sampling method in this study is non-probability sampling with a sampling technique, namely snowball sampling.
Referring to the opinion of Hair et al. (2010) in (A. Yunita, 2012), the sample size in the study must have a minimum sample size of five times the number of questions analyzed. The number of statements in the questionnaire in this study was 20 questions then multiplied by 5, so the number of samples in this study to produce good results was at least 100. And in this study, the number of respondents used was 134 respondents.
The primary data were derived from questionnaires distributed to respondents who live in Medan and have directly visited (dine-in) a modern coffee shop at least once in the last year. Coffee shops offer promotions to participants ages 18-60 years because they can answer and understand each questionnaire question objectively. To obtain the results of the effect of the marketing mix on repurchase intention, the author uses multiple linear regression data analysis techniques and simple linear regression using SPSS 22.00.
A consumer segmentation analysis was carried out by using the K-means algorithm. K-means algorithm seeks to find the minimized squared error between the mean points of clusters. Suppose µm is the mean point of cluster cm. Therefore, a squared error between average points in cluster cm can be formulated as follow.
Therefore, the sum of squared error between average points of all clusters is minimized, formulated as follows.
This study performs the segmentation purpose employing rapidminer studio 9.9.000 was utilized. The analysis process was drawn in figure 2. Moreover, the Support Vector Machine (SVM) algorithm was used to have more information on attribute importance. SVM was first introduced by Vladimir N Vapnik and Alexey Chervonenkis. The purpose of this algorithm is to handle the analysis of classification and regression. The investigation is basically to solve the problem of lagrangian optimization as follows.

Statistical Modelling using SPSS Software
Testing of the hypothesis is carried out using multiple regression analysis. Multiple linear analysis is used to determine the influence of the marketing mix consisting of the product (X1), place (X2), price (X3), promotion (X4) on customer satisfaction (Y). The multiple linear regression values can be seen in Table 1 below. From the regression, it can be explained as follows: a. The regression coefficient (X1) of 0.457 means that if the product is increased by one unit, customer satisfaction at the modern coffee shop in Medan will increase by 0.457, assuming the other variables are constant.
b. The regression coefficient (X2) of 0.389 means that if the place is increased by one unit, customer satisfaction at a modern coffee shop in Medan City will increase by 0.389, assuming other variables remain. c. The regression coefficient (X3) of 0.148 means that if the price increases by one unit, the customer satisfaction at the modern coffee shop in Medan City will increase by 0.148 with the assumption that other variables are fixed. d. The regression coefficient (X4) of 0.030 means that if the promotion is increased by one unit, then customer satisfaction at the modern coffee shop in Medan will increase by 0.030, assuming other variables remain.
The following table below is the result of the determination test.  (2021) Based on Table 2, regarding the test results of the coefficient of determination (R 2 ), it can be seen that the Adjusted R-Square value is 0.820. Customer satisfaction can be explained by 82% by the product, place, price, promotion (marketing mix), while the remaining 18% is influenced by other variables not examined in this study.
A simultaneous test (F test) is used to observe whether the independent variable simultaneously has a significant effect on the dependent variable. The basis for decision making in the F test is if the value of Fcount > Ftable and a considerable value < 0.05, then the independent variable simultaneously has a significant effect on the dependent variable. If the value of Fcount < Ftable and significant value > 0.05, then the independent variable simultaneously has no significant impact on the dependent variable. Following are the simultaneous test results which can be seen from the table below:  and sig 0.000 < 0.05, it can be concluded that the marketing mix consisting of product, place, price, promotion together has a significant effect on customer satisfaction in a modern coffee shop in Medan.
Partial test in multiple linear regression analysis aims to determine whether the independent variable (X) partially has a significant effect on the dependent variable (Y). If tcount > ttable, the independent variable (X) affects the dependent variable (Y). If the sig value < 0.05, the independent variable (X) has a significant effect on the dependent variable (Y). Suppose the sig value > 0.05, the independent variable (X) has no significant impact on the dependent variable (Y). Here are the partial test results. Based on table 4 above, it can be concluded that the test results of each independent variable are described as follows: a. The product variable (X1) shows the tcount of 8.360 > ttable 1.978 and sig 0.000 < 0.05 so that H1 is accepted and H0 is rejected, meaning that the product has a significant effect on customer satisfaction a modern coffee shop in Medan. b. The place variable (X2) shows the value of tcount6,596 > ttable 1.978 and sig 0,000 < 0.05 so that H2 is accepted and H0 is rejected, meaning that place has a significant effect on customer satisfaction at a modern coffee shop in Medan. c. The variable price (X3) shows the value of tcount 2.244 > ttable 1.978 and sig 0.027 < 0.05 so that H3 is accepted and H0 is rejected, meaning that price significantly affects customer satisfaction at a modern coffee shop in Medan. d. The promotion variable (X4) shows the tcount value of 0.392 < ttable 1.978 and sig 0.696 > 0.05 so that H4 is rejected and H0 is accepted, meaning that promotion has no significant effect on customer satisfaction at a modern coffee shop in Medan. The simple linear regression values can be seen in Table  5 below: e.  (2021) Based on the results of data processing in Table 5, the simple linear regression equation model can be formulated as follows: Y = 0.814 Z. The regression coefficient (Z) of 0.814 indicates that the customer satisfaction variable has a positive effect on repurchase intention. The customer satisfaction is increased by one unit, then the repurchase intention of a modern coffee shop in Medan will increase by 0.814, assuming other variables remain. The following table below is the result of the determination test: The coefficient of determination (R 2 ) which is determined by the R square, is 0.662. The 66.2% of repurchase intention can be explained by customer satisfaction, while the remaining 33.8% is influenced by other variables not examined in this study.  Table 7 reveals customer satisfaction variable (X) shows the value of tcount 16.093 >ttable 1.978 and sig 0.000 < 0.05 so that H5 is accepted and H0 is rejected, meaning that customer satisfaction has a significant effect on repurchase intention at a modern coffee shop in Medan.

Segmentation Analysis Using Rapidminer Studio 9.9.000
Segmentation analysis was conducted by utilizing the K-means algorithm. Three clusters were identified as cluster 0, cluster 1, and cluster 2 (figure 3). Cluster 0 is occupied by the range of 4.53 to 5, which gathers the highest score answered by respondents. Twenty-eight respondents are categorized into this cluster. Cluster 1 is occupied by the range of 3.48 to 4.37 as the middle-range level of the respondent. A total of 43 respondents are categorized into this cluster. The last cluster is cluster 2, which is the most dominant cluster in this study. Sixtythree respondents were grouped into this cluster. The range of respondent's answers is started from 2.3 to 3.52 at the highest level. More complete results are described in table 8.  The study of each cluster was further conducted to bring the results into practical implementation. In addition, the respondents are asked to share their information on modern coffee shop consumption. The coffee shop was brought to the analysis to see their initial experience consumption in Medan city. Furthermore, each characteristic respondent (age and living location) categorized into a specific cluster was analyzed. The analysis is presented in table 9. The data reveals that cluster 0 contains 11% of respondents under 18 years old, and all of them have tried the modern coffee shop. Besides, More than 90% of them are living in Medan city. These salient results indicate the modern coffee shop acceptance of youngsters in Medan. In cluster 3, 97% of the respondents are 18-35 years old, and 92% live in Medan City. However, 73% of the respondents here have never tried to consume modern coffee shops. Besides, 3% of youngsters categorized into these clusters have never tried the modern coffee shop. From the collection's characteristics, each set contains a different part of respondents (consumers).
Consequently, a different marketing approach to other clusters is required for inducing buying. The statistical modeling analysis in prior analysis has strengthened the phenomenon explanation. Place, product, and price were found to have a significant influence on customer satisfaction. However, as the results of segmentation analysis increase the repurchase intention, a diverse marketing mix approach is recommended since each cluster has a distinct characteristic. Therefore, for future research, designing a marketing strategy concerning collections is a promising research area.
The importance of indicators in predicting the different clusters employs a Support-Vector-Machine-Weighting analysis was performed. The result is described in figure 4. Based on the weighting variables result, the attributes U and A (product) are the most influential than the other attributes in predicting clusters that were earlier identified in this study. The result emphasizes the importance of product quality from a consumer perspective. The development was also supported by the partial statistical analysis conducted earlier, showing the significant effect on customer satisfaction. Therefore, statistical modeling and segmentation analysis emphasize the importance of product quality to customer satisfaction to increase repurchase intention.

DISCUSSION
Simultaneous test results show that the marketing mix consisting of product, place, price, promotion together has a significant effect on customer satisfaction at a modern coffee shop in Medan. These results indicate that the better the marketing mix management, the better the customer satisfaction with the contemporary coffee shop in Medan. However, the segmentation analysis result encourages the marketing mix strategy to be devised concerning its cluster characteristics. The results of this study are supported by the results of research conducted by (Kusuma & Suryani, 2017), which show that the marketing mix has a positive and significant effect on customer satisfaction. The finding (Sudari et al., 2019) shows that product, promotion, place, and price positively affect customer satisfaction with food and beverage products.
The partial test results show that the product significantly affects customer satisfaction at a modern coffee shop in Medan. The service has fulfilled the respondents' need for aroma, typical taste, or high-quality coffee ingredients. The results of this study support the previous research of (Setyandi & Satrio, 2018), which concluded that the product affected the customers' satisfaction. Moreover, the partial test results show that the place significantly affects customer satisfaction at a modern coffee shop in Medan. The results of this study are supported by the research of (Kamaluddin, 2018) which concluded location has a positive and significant effect on customer satisfaction. The partial test results show that the price significantly affects customer satisfaction at a modern coffee shop in Medan. Based on the study results, the respondents considered that the price set was following the quality of the product given. The results of this study support previous research, (Effendy, 2019), which shows that price has a positive and significant effect on consumer satisfaction.
Besides, the partial test results also show that promotion has no significant effect on customer satisfaction at a modern coffee shop in Medan. The advertising does not affect customer satisfaction. Promotions that are carried out are still not very intensive, so that many consumers do not know detailed information about the modern coffee shop. In addition, advertisements carried out tend to be the same as other cafes, so they are not significant in building customer satisfaction. The dominant motive for consumer decisions to visit coffee shops in Medan is to relax and eat and drink. Consumers get information about the most visited coffee shops from friends' recommendations (S. Sara, T. Sebayang, 2013).
The partial test results show that customer satisfaction significantly affects repurchase intention in a modern coffee shop in Medan. This study indicates that the higher the level of customer satisfaction, the more consumers tend to buy back at a modern coffee shop in the future (repurchase intention). The results of this study are supported by the results of research conducted by (A. Sari, D. Siti A, 2020); (R. Arlanda, 2018); (Kusuma & Suryani, 2017), which show that customer satisfaction has a positive and significant effect on repurchase intention.
Overall, this study confirms that in the COVID-19 pandemic currently being faced, including in the coffee shop industry, customers continue to visit modern cafes mainly due to product quality. Public awareness to consume clean, healthy, and guaranteed products are becoming increasingly important. In addition, the place is the second most crucial variable considering that during a pandemic, health protocols are very much considered by customers, such as strategic location, the distance between benches, and other health protocols. The third variable that has an effect is price, whereas, in Indonesian society, one of the characteristics of consumers is the focus on cost. Furthermore, pandemic causes all levels of the organization to be affected to reduce their level of consumption. This price becomes an influential variable. And the last variable that has a positive but insignificant effect is promotion because the promotions that have been carried out tend to be the same as other cafes so that they are considered the same as other cafes and beverages. Therefore, a modern café shop needs to continuously improve product quality, place, and price to increase customer satisfaction and ultimately increase customer loyalty. As for promotion, it can only be maintained at this time.

FURTHER STUDY
The managers of modern coffee shops in Medan must be more sensitive to price competition in the market. The prices set the modern coffee shop acceptance. The customers are also satisfied with the offerings by a strategic location to attract new customers. Coffee shops in Medan can continue to grow by promotions on an ongoing basis of introducing products. The results of segmentation analysis encourage a marketer to devise a diverse marketing mix approach to each identified cluster with distinct characteristics. Therefore, designing a marketing strategy concerning clusters' characteristics is a promising research area for future research.