Reading and understanding data to solve problems is one of the essential educational competencies in the era of the 4th Industrial Revolution. Therefore, product sales application services need to be expanded in convergence education using design and data. As a small business owner in Korea, marketing and promoting inventory is a problem that must be solved to increase income, and small business owners have difficulty solving these problems unless they leave them to inventory management companies or public relations companies. This paper introduces the implementation of applications for small business owners based on product sales applications. The difference from existing product sales platform applications is that it improves usability by adding discounts on inventory, discounts on non-crowded times, and offline promotion service functions linked to apps and signage. The purpose of this paper is to propose an application that supports inventory discounts for small business owners, non-crowded discount sales, and services linked to apps and signage. In conclusion, this paper aims to present a way for both consumers and sellers to reap mutual benefits by providing opportunities for services different from conventional methods in product sales application services. If education using digital data is provided in the service design field in the future, it can be expected to improve the competitiveness of small business owners and increase sales.