Currently, the development of marketing strategies, consisting of segmentation, targeting, and positioning, is being adjusted to the customization of online service businesses in Thailand. This research aims to develop a segmentation strategy, targeting, and positioning to increase the efficiency of service businesses in the online world and analyze the confirmatory factor of a segmentation strategy, targeting, and positioning to increase the efficiency of service businesses in the online world. This study is mixed research, collecting and analyzing both quantitative and qualitative data. The data analysis for this research uses confirmatory factor analysis theory (CFA) to summarize branding strategies for 800 online food businesses in Thailand, and the Fuzzy Set Theory to analyze qualitative research data from a group of 19 expert opinion questionnaires. The researcher found that the model for the development of marketing strategy for online service businesses in Thailand, consisting of segmentation (SM), targeting (TG), positioning (PN), and customization (CM), is consistent with the empirical weighting factor with the highest value. The values are as follows: Segmentation (SM) = 0.99, Customization (CM) = 0.98, Targeting (TG) = 0.97, and Positioning (PN) = 0.88. Therefore, future marketing strategies should consider customer needs for positioning with customization and generating profits for the business, as this is the most effective marketing strategy. The findings of this research have important implications for online service businesses in Thailand, as they provide a framework for developing effective marketing segmentation strategies, targeting, and positioning.