<p>Although customer categorization has long been regarded as a key practice for promoting sales outcomes, its communicative dimensions have received limited analytical attention. This paper examines customer categorization as an interactionally accomplished phenomenon embedded in sales interaction. Drawing on Membership Categorization Analysis of video-recorded interactions in Japanese jewelry retail stores, the study demonstrates that customer categorization is systematically integrated into salespersons’ persuasive actions that encourage customers to consider purchasing products. The analysis identifies two broad categorization practices. The first involves categorizing co-present customers, often through inferences based on appearance. This practice functions as a customer-targeting resource that establishes a relationship between particular products and customers without explicit reference to articulated needs. By invoking normative category–predicate relations and mobilizing hypothetical others’ preferences, salespersons implement suggestive selling at an early stage of the encounter. The persuasive force of such categorizations is further strengthened through salespersons’ professional expertise and accumulated experience. The second practice concerns categorizing absent but relevant potential users, particularly in gift-purchasing situations. Here, salespersons infer attributes of absent users from information provided by co-present customers and mobilize imagined customers to support adaptive selling. The analysis also shows that categorization may involve multiple individuals and include salesperson self-categorization as a persuasive resource. Moving beyond cognitive accounts, the study highlights customer categorization as a dynamic, locally produced mechanism through which customer segmentation and adaptive selling are accomplished in situ.</p>