The development of ICT (Information and Communications Technology) through the widespread use of mobile devices has been influencing consumers’ consumption behavior. In particular, various social network platforms, based on the sharing economy, have been highlighted as one of the alternatives to solve the concerns of the current consumption culture such as over-consumption and environmental problems. One of the most popular business models of the sharing economy in tourism industries is an accommodation sharing service such as Airbnb. Couchsurfing, as another example of accommodation sharing services, has recently gained attention for its non-profit characteristics of a business model. In fact, a significant number of users (hosts) in Couchsurfing are voluntarily offering a place to stay for other users (couchsurfers) who have never met before. However, why hosts help strangers in this non-profit sharing economy website is not well understood: there is no economic benefit to the host. Therefore, based on social capital theory and prior literature, this study identifies and validates important influencing factors on hosts’ intention to share accommodation in a non-profit sharing economy website. After gathering survey questionnaire data from users in Couchsurfing, the empirical analysis is conducted to test the proposed research model. The findings of this study reveal the specific reasons of users’ participation in non-profit online accommodation sharing services in which the economic benefit is not guaranteed. Moreover, it would provide some practical insights as to how managers can encourage users’ participation in sharing economy platforms.