Uber, a ride-sharing service, is a unique example of how technology can connect people. It has the potential to transform transportation by providing a technology-mediated marketplace for transportation of people and goods. This paper presents an ethnographic study of ride-sharing via Uber with a focus on examining the roles of technology and trust in this new marketplace. The authors used a grounded theory approach to interpret and analyze emergent themes collected from one of the author’s journals, interviews, and service logs as well as official documents and text messages. This analysis was used to develop a theoretical model that emphasizes the role of signals in developing expectations, clarifying roles, and adapting trust.