This research applies attachment theory to a pivotal question in relationship marketing: Which consumers have a propensity to build strong relationships with companies/brands, and why? Using data from a longitudinal field study in the automotive services category, we first show that secure personal attachment drives stronger commercial relationships, as measured by dealer trust, satisfaction, and loyalty. Building upon recent theory supporting domain-specific instantiations of generalized attachment orientations, we then provide evidence of improved diagnostic and predictive value from an attachment construct specific to the commercial (versus personal) relationship context. Two dimensions of secure consumer attachment —embrace of vulnerability and drive for closeness—are empirically derived; these facets drive different relationship marketing responses. The effects of secure consumer attachment are persistent over time, and manifest despite controls for other traits known to drive relationship behaviors. Our result patterns parallel those found in interpersonal relationship settings and support the application and extension of attachment theory in marketing. The research offers further validation of the contention that commercial relationships behave in similar ways to personal relationships, thereby reinforcing the legitimacy of inquiries that seek to develop relationship theories in consumer marketing research.