The goal of this research is to determine whether a local brick-and-mortar (B&M) business should implement an online-to-offline (O2O) strategy, as well as the conditions under which each mode is most effective. This research examines how an O2O platform and a B&M store's (like restaurants) decision-making processes interact in a two-echelon supply chain (SC). This research employs numerical experiments and a mathematical approach to address research issues with an online food ordering service "Snappfood" that delivers from over 1,500 eateries. We first look at five case studies in which the retail price of Snappfood is determined in both a normal situation (without a marketing mechanism) and one in which the store invests in local advertising to boost demand in the self-building channel. A growth in SC profits is predicted by numerical experiments conducted under this model. The findings of decentralized decision-making reveal that in self-building mode, the store decides on both retail channels and the level of local advertising investment. In turn, the O2O platform recommended a payment delay contract as a fixed operating method for working with B&M stores. This is one of the first studies to investigate at the online sales of a local B&M store, which has the unique characteristic of offering home delivery. Second, we suggest and evaluate that a B&M store can use either the self-building technique or implementing an O2O platform for online selling.