“The influence of co-branding strategies on repurchase intention: Empirical evidence on cosmetics and herbal medicine collaboration product in Indonesia”

During collaboration strategies, companies combine two or more products with different characteristics. This strategy is interesting to research because it is an out-of-the-box strategy. In general, brand partnerships usually occur between companies with similar values, missions, and consumer target markets. This study aims to examine the effect of co-branding and promotions on customer-based brand equity and re-purchase intentions with customer-based brand equity as a mediator. This paper used a quantitative approach. Data collection was carried out through online surveys distributed among 115 buyers of a collaborative product of Upmost Beauté cosmetic item and Tolak Angin herbal medicinal item in the city of Semarang, Central Java Province, Indonesia. Data analysis used regression tests and Sobel tests with SPSS 24.0 software. The research results found empirical evidence that co-branding and promotions increase customer-based brand equity, and customer-based brand equity increases re-purchase intentions. These results also reveal the mediating role of customer-based brand equity in contributing to increased repurchase intentions. Co-branding and promotional strategies increase repurchase intentions through customer-based brand equity. Companies should focus on co-branding strategies, promotions, and customer-based brand equity to attract more consumers to repurchase Upmost Beauté and Tolak Angin collaboration product.


LITERATURE REVIEW
Repurchase intention is a factor that encourages individuals to buy certain products.This intention arises if consumers feel that the product they buy provides benefits that match their wishes.According to Kotler and Armstrong (2010), repurchase intention is a person's tendency to buy the most preferred brand.Fang et al. (2014) stated that repurchase intention is a customer's tendency to buy products from the same manufacturer in the long term.Repurchase intention is retention, according to Wu et al. (2014).Retention is frequently considered the most crucial factors in relational marketing.Similarly, repurchase intention, according to Lin and Lekhawipat (2014), might encompass not just the desire to repurchase the items but also the intention to recommend them to friends and family.Businesses should consider repurchase intention when attempting to increase sales of goods and services (Ali, 2019).
Before a consumer buys a product, he/she will seek information from personal experience and input from other people about the product needed.After getting the information, consumers decide which product to buy.The indicators are the existence of references, interest in the product, and the belief that the brand is able to meet needs.Meanwhile, Keller and Swaminathan (2019) concluded that repurchase intention is measured through transactional, referential, preferential, and explorative intentions.
When two or more well-known brands are integrated into a single offer, this is co-branding.Kim et al. (2007) defined co-branding as a corporate partnership in which businesses remain independent while working together on marketing, production, and space sharing.Co-branding, according to Leuthesser et al. (2003), is the introduction of two brands into a marketing environment, such as distribution channels, product placement, and advertising.Meanwhile, Kotler and Keller (2016) stated that co-branding is a combination of two or more well-known brands in one offer.Cobranding is a collaboration between two or more companies to produce a new product that is expected to increase sales (Korua et al., 2021).Cobranding is successful when partner brands enhance the alliance and raise the degree of partner brand equity (Grebosz, 2012).If the two companies doing co-branding can offer short messages to the targeted audience, this could be a successful marketing campaign (Gaille, 2016).
Co-branding is a development in marketing that has received widespread attention from academics and practitioners.It is expected to meet the needs according to what the market wants (Korua et al., 2021) by integrating both companies' activities and operations to achieve a common goal.This cobranding occurs when individual or constituent brands form one identity and are sold as composite brands (Warraich et al., 2014).With co-branding, there is synergy (co-synergy) where one brand can strengthen other brands to further strengthen consumer appeal.Thus, co-branding can increase sales through existing target markets and open opportunities for new consumers and networks.
By linking themselves with other companies, each of these firms hopes to attract new consumers through co-branding, especially if it takes the form of joint packaging.This kind of reaction can be a feeling of warmth, fun, comfort, joy, security, closeness to the social environment, and self-esteem.This will increase the success of the brand, impacting consumer attitudes toward the brand and forcing consumers make repeated purchases.Kim  Activities that convey a product's excellence and convince target consumers to purchase it are referred to as promotions.Kotler et al. (2022) stated that promotion is an action that conveys the superiority of a product and convinces target consumers to buy.Meanwhile, sales promotion is a marketing investment activity that produces brand equity resulting from past marketing investments (Aaker, 1996).According to Kotler et al. (2022), sales promotions are marketing tools designed to stimulate faster and larger purchases within a limited period.Ailawadi et al. (2003) found that price promotions have a long-term positive impact on strengthening purchases and brand performance.Similarly, Chung and Lee (2003) found that the higher the sales promotion, the greater the influence on consumers' repurchase intentions.
A brand is more than just a product; it has a dimension that differentiates it from other similar products.This distinction needs to be logical and evident in how a brand's product performs, or it may be more symbolic, sentimental, and intangible in how a brand is represented.A brand may be represented by a name, trademark, logo, or by a mix of these.Customer-based brand equity is a framework for brand equity that looks at it from the customer's standpoint (Yoo et al., 2000).Keller (2001) and Keller and Swaminathan (2019) explain that customer-based brand equity is the difference in the influence of brand knowledge on consumer responses to brand marketing.In contrast, Marques et al. (2020) defined brand loyalty as a resolute and unwavering commitment to stick with and support a brand in the face of rival opposition.Marques et al. (2020) stated that brand equity is a crucial subject in branding, marketing, and management research, as higher brand equity levels are frequently linked to improved cash flow and increased competitiveness.
The fundamental idea behind customer-based brand equity is that a brand's strength may be determined by the experiences of customers who have been studying, sensing, seeing, and hearing about the brand for a while.This notion stresses the conceptualization and evaluation of individual customers; firm-based brand equity concentrates brand value on companies (Simon & Sullivan, 1993;Leone et al., 2002).Most people agree that brand equity is the additional value a brand adds to a product, regardless of the many research streams and methodologies used (Farquhar, 1989).Wang et al. (2021) believed that brand equity is maintained in the minds of consumers and is reclaimed after product purchases.According to Romaniuk and Nenycz-Thiel (2013), customer-based brand equity can influence buying behavior.Bakhshizadeh and Aliasghari (2023), who support this claim, assert that a consumer's willingness to use a product or service increases with brand equity and considerably affects intention to repurchase.
This study relates co-branding, promotion, brand equity, and repurchase intention to investigate the effect of co-branding and promotion on customerbased brand equity and repurchase intention, as well as the effect of customer-based brand equity on repurchase intention.Customer-based brand equity serves as a mediating structure that influences repurchase intention.
This study aims to examine the effect of co-branding and promotions on customer-based brand equity and repurchase intentions with customerbased brand equity as a mediator.Figure 1 shows the conceptual framework.

METHODOLOGY
This deductive research uses a quantitative approach.The population comprises consumers who have shopped at several retail stores in the Pedurungan and Tembalang Districts.These two sub-districts were chosen because their population is denser than other sub-districts in Semarang City.The gender composition is 49.50% for men and 50.5% for women.Productive age is quite high, which shows that the level of consumption of goods and services is also quite high.
The Upmost and Tolak Angin co-branding products are unique collaboration products, so consumers of the upper middle class are expected to be interested in them.The exact number of population is unknown, so the study uses Cochran formula to determine the number of samples.where n -Sample, z -Prices are in the normal curve for a 5% deviation, with a value of 1.96, p -50% correct chance, q -50% chance of being wrong, e -10% margin of error.The result is n = 96.04.
The number of samples calculated above as a benchmark that the minimum sample that is eligible to be used is 96.04.This study uses a sample of 115 respondents to make the selected sample more representative.

RESULTS
The questionnaires were distributed at outlets or counters that provide or sell Upmost Beauté and Tolak Angin products.The distribution lasted for approximately two weeks with 150 questionnaires.Of these, 115 questionnaires can be processed, as 20 were incomplete and 15 were damaged.Table 2 shows the description of the co-branding variable.Six indicators indicate that the two products are well known to the public because of their good quality; this can be seen from the mean value = 4.However, there were respondents who disagreed with this idea.This shows that the respondents did not understand and felt strange about the collaboration between herbal and cosmetic products.Note: Strongly Disagree (SD), Disagree (D), Neither Agree nor Disagree (KA), Agree (A), and Strongly Agree (SA).
According to Table 3, respondents favorably responded to the promotion indicators; this shows that the promotion was acceptable to the community.However, many respondents only somewhat agreed because they did not understand cosmetics co-branding with herbal products.Note: Strongly Disagree (SD), Disagree (D), Neither Agree nor Disagree (KA), Agree (A), and Strongly Agree (SA).
Customer-based brand equity is a method of building brand equity that is based on what consumers have learned, experienced, seen, and heard about a business over time.In Table 4, respondents are already familiar with Upmost's co-branding products; cosmetic products are well known to teenage consumers, while Tolak Angin is an herbal medicinal widely known by Indonesian people.Although some respondents somewhat disagreed with the co-branding product, this was due to their lack of familiarity with cosmetic products.Note: Strongly Disagree (SD), Disagree (D), Neither Agree nor Disagree (KA), Agree (A), and Strongly Agree (SA).
Table 5 shows that the respondents are very interested in making repeated purchases, considering that these products are already known to respondents and are widely used both for health and appearance.In addition to respondents who agreed to repurchase, some respondents disagreed.This could be due to disagreement with co-branding between herbal items and cosmetics.In the opinion of the respondents, there is cooperation in products that are not of the same type.
Validity testing is conducted to determine how accurate an instrument is in measuring what it wants to measure by using a factor analysis test.
A sample adequacy test was carried out using the Kaiser-Meyer-Olkin (KMO) value, where the KMO value was > 0.5.The sample is considered sufficient if KMO > 0.5.The validity test is carried out by determining the loading factor (LF) value; the instrument is considered valid if the LF value is > 0.5.Table 6 shows the results of the validity testing.
A reliability test determines whether measuring items are consistent and whether repeated measurements yield the same findings dependable if evidence from many periods has commonalities.This method of dependability testing makes use of an analytical approach of Cronbach's alpha.If α is more than 0.7 in this reliability test, it is deemed dependable.According to the reliability test findings displayed in Table 7, every variable is reliable (Cronbach's alpha > 0.7).This indicates that the questionnaire instrument is trustworthy and dependable, making it suitable.Next, Table 8 shows coefficients of determination with the adjusted R-square values.Based on Table 9, the F significance (F-test) value for both models was significant at 0.000 < 0.05, which means that the regression models for both models met the goodness of fit requirements so that they were feasible to use.Further, linear regression analysis is used to measure the strength of the influence of co-branding and promotions on customer-based brand equity and repurchase intention.Regression analysis for model 1 (Table 10: CBBE = 0.434 COB + 0.43 PRO) shows that co-branding and promotions have a positive effect on customerbased brand equity.The stronger the co-branding and the more intensive the promotion, the better understanding of brand equity.Both co-branding and promotion have a significant effect on increasing brand equity at a significance of less than 1%, so H 1 and H 2 are accepted.Based on Table 11, co-branding and brand equity have a significant effect on increasing consumer repurchase intention at a significance of less than 1%.Moreover, promotions have a significant effect on increasing consumer repurchase intention at a significance of less than 5%.Thus, H 3 , H 4 , and H 5 are accepted.
According with Baron and Kenny (1986), a variable is a mediator if it affects the correlation between predictor (independent) and criterion (dependent) variables.According to the mediation model, the independent factors affect the mediator variables, which in turn affects the dependent variable.In this study, the independent variables were co-branding and promotion while the dependent variable was repurchase intention.Customerbased brand equity is a mediating or intervening variable.Indirect effects in this study were tested using the Sobel test to determine the value of the indirect effect on each path.
Path A is: Sobel test of COB (co-branding) against REP (repurchase intention) mediated by CBBE (customer-based brand equity).Table 12 shows the path mediation coefficient = 0.3245 and the significant level p < 0.05, namely p-value = 0.0018 < 0.05.This shows that customer-based brand equity mediates the effect of co-branding on consumer repurchase intentions.Consumers can distinguish between two partnered brands; therefore, Sobel test provides empirical evidence that customer-based brand equity mediates co-branding and promotion relationship on consumer repurchase intention.Thus, customer-based brand equity is a critical component in a business, because it shows that a company has more value than its competitors.Therefore, building brand equity is vital for business activists because surely every company strives to achieve positive brand equity.Consumers will choose products from that brand over other products outside the brand, and will be willing to pay for the product at a high price even though consumers can get the same thing from other brands.

CONCLUSION
This study aims to determine the effect of co-branding and promotion on customer-based brand equity and repurchase intention in the collaboration of Upmost Beauté cosmetic product and Tolak Angin herbal medicinal product in Semarang, Indonesia.First, it was found that co-branding had a significant positive effect on customer-based brand equity and repurchase intention.This means that customer-based brand equity and repurchase intention will increase with Upmost Beauté and Tolak Angin co-branding.Second, promotion positively affects customer-based brand equity and repurchase intention.This indicates that intensive promotions increase customer-based brand equity and repurchase intention.Third, customerbased brand equity mediates the influence of co-branding and promotion on repurchase intention.
The findings indicate that customer-based brand equity takes a strategic role as a mediator for co-branding and promotions in influencing consumers` repurchase intentions.This means that companies must use customer-based brand equity to strengthen the influence of co-branding and promotions so that consumers` repurchase intentions are increased.Similarly, with intensive promotional programs and many discounts on certain purchases, the collaboration of two well-known products will attract customers and increase their repurchase intention.

Table 1 .
Profile of respondents

Table 1
describes the profile of research respondents; most are aged between 17-26 years.This shows that the users are teenagers and adults.In this regard, they are those who like new things and cosmetic products, as they are curious.Male respondents constitute 19.1%; they primarily purchased the Tolak Angin product, while the Upmost Beauté cosmetic products were given to people close to them.

Table 4 .
Customer-based brand equity indicators

Table 7 .
Reliability test

Table 9 .
F-test for models 1 and 2

Table 10 .
Regression analysis for model 1

Table 11 .
Regression analysis for model 2

Table 8 .
Determination test of models 1 and 2

Table 12 .
Indirect effect and significance using normal distribution of path A

Table 13 .
Indirect effect and significance using normal distribution of path B