The purposes of this research are to investigate the nature of an individual's commitment to companies, particularly service providers, and to develop and test a model of the antecedents and consequences of consumer commitment. Commitment is defined as an affective attachment and an intention to develop and maintain long-term relationships with exchange partners (cf. Rusbult 1983). We identify three types of motivation leading to commitment formation: relationship quality, expectation of reciprocity, and dependency. These three sets of factors reflect three different routes to commitment. Consumer commitment produces behavioral consequences beneficial to companies. In this research, we focused on two categories of behaviors (relationship growth and communication behaviors) and two types of behavioral intentions (tolerance with service recovery and price tolerance). To date, research on service relationships has centered its attention on satisfaction and trust, simply one route to commitment. In this research, we developed and tested a model of consumer commitment that incorporates the possible three routes to commitment. In the process, we also invented measures of the new constructs in the proposed model. These measures were pre-tested with two consumer services before the main survey was launched. Based on the pretest results, we revised the measures and reported our preliminary findings. Subsequently, we conducted a qualitative and an empirical study. We estimated the proposed model, tested its robustness, and tested the influence of potential moderators of relationship length and prior experience. We found the model to be reasonably robust across contexts and were able to shed some light on the moderating influence of the two moderators on the relationships between consumer commitment and its antecedents. Out of seven hypotheses, five were supported and two were partially supported. In summary, this research advanced our understanding of the nature of consumer commitment and extended commitment research into a new domain (i.e., consumer-firm context). The proposed structural model related the commitment construct to its antecedents and consequences and provided supporting empirical evidence from the service context. Findings from the studies also generated additional insights into the changes of relative influences of commitment antecedents when taking into account the length of relationships and prior experience. We concluded with theoretical contributions, managerial implications, limitations and future directions of this research.