The purpose of this paper is to explain why the number of participants in the Tour de Okinawa has been increasing during the past twenty years, focusing on the supply-side. Previous research has mainly analyzed participants’ incentives and judgments about the event product’ s overall excellence from the demand-side perspective, which does not clearly explain the marketing effectiveness of the Tour de Okinawa. Because the Tour de Okinawa organizer was not a profit organization, its marketing activities confronted resource constraints that indicated we should consider the effects of the situation. Therefore, we focused upon the marketing activities and methods to overcome the resource constraints. The result shows that the organizer incorporated their organization as a nonprofit corporation, which stabilized their finances so that marketing mixes were improved. The improvement of the marketing mix was also aided by accumulated marketing know-how about the event, which occurred after hiring experts because of the financial stability. These activities by the organizer explain the reason why the number of participants in the event has been increasing.