The endowment effect describes the phenomenon that individuals are willing to pay less to buy an object or service than they would need to be payed to sell the object or stop using the service. This classic effect from behavioral economics and psychology could also be observed for the usage of social media platforms such as Facebook. However, it is unclear how personality and average time spend on social media platforms are associated with the strength of the endowment effect in the context of social media services. Moreover, it is not clear how individual differences in the endowment effect associate with tendencies towards disordered social media use. As the endowment effect has not been investigated for Chinese social media applications, yet, we will conduct the study in China with a focus on WeChat (and Sina Weibo, QQ, and DouYin (TikTok)).