Willingness to share trips and surge pricing schemes remain unexplored areas in ridesourcing research. This study first conducts an explorative spatiotemporal analysis on both features’ interdependencies, that is, willingness to share and surge pricing. The willingness-to-share behavior is analyzed with respect to its econometric and psychological aspects. Mile-price and hour-of-day are used as proxies for the elasticity and psychological perception of security to share rides with strangers, respectively. Surge pricing is discussed within the classic economic theory on supply and demand dynamics, as well as other factors such as traffic conditions and trip length. The willingness-to-share pattern mined in this analysis is further analyzed in a behavioral market segmentation context to identify the type of underlying existing spatiotemporal trends. The proposed methodological protocol builds on mining spatial heterogeneity and temporal trends to provide a comprehensive understanding of the willingness-to-share behavior. The study uses the large ridesourcing dataset collected in the City of Chicago to showcase the implementation and provides a critical and contextual discussion on the behavioral segmentation pattern and the underlying urban socioeconomic fabric. Two types of oscillating and sporadic trends were captured in statistically significant hot and cold willingness-to-share spots that relate to more and less socially disadvantaged community areas, respectively. Two regression models were developed to identify the determinants of the observed trends. The non-white population percentage, percentage of low-income households, and a younger population exhibit significant positive relationships with more willingness-to-share ridesourcing trips.