“…Promo codes also can be a promoting tool in crowded places (such as the mall, parks, and supermarkets), commuting transit places (terminals, stations, and bus stops), or on social media. It will be another positive value-adding if the promo codes can be flexibly used (Sandika 2018). Another cost-centric strategy is providing price discounts during the first month of using the app (Wang et al 2020), end of the month, or at certain moments, such as payday, religious holiday, customer's birthday, or national holiday.…”