Intelligent machines are steadily replacing human workforce in retail and service. Although customers' short-term responses toward service robots are well understood, little is known about the potential long-term effects of replacing humans with robots in these settings. Drawing on social perception theory, the Stimulus–Organism–Response (SOR) model, and speciesism theory, the current research examines whether and how human and robotic service workers influence customers' loyalty responses depending on whether these living and nonliving entities acknowledge customers. Across three experiments and a series of different shopping settings (N = 1541), we expose customers to human (vs. robotic) service workers who do (vs. do not) acknowledge them through eye contact. A human (vs. robotic) acknowledgment was found to result in significantly more favorable loyalty responses; an effect mediated by the perceived warmth and, to a lesser extent, the perceived competence of the service workers. These findings hold across embarrassing (e.g., shopping for lingerie or sex toys) and non-embarrassing (e.g., shopping for shoes) settings, offering generalizable insights for managers and scholars concerned with the outcomes of implementing innovative human-centric technologies in various consumption contexts.