With the widespread use of virtual store applications such as Shopee, it is imperative to increase the awareness of potential buyers to choose trusted products and stores. Store reviews are one of the essential bases on which buyers determine whether or not they will buy the products. Buyers can see the language used by the reviewers; whether the review assess the products positively or not especially when the online shop owner replies to these reviews. This has encouraged the researchers to conduct a sociolinguistic study on the registers used in product reviews. The data for the study was taken from the Shopee platform. Sociolinguistic theoretical approach as proposed by Fishman (1972) with a focus on interaction patterns, studies of language barrels, and language functions has been used in this study. The results of this study show how the interaction patterns, language tunings, and language functions occur in the @izdihaar_olshop13 store reviews. Based on the analysis in giving reviews in online stores, there are two patterns of interaction found; the interaction pattern between individuals and groups, and the interaction patterns between groups and groups. In addition, there are two kinds of language variation used namely casual language variety and consultative language variety. The study also found two language functions realized in the reviews namely expressive functions and referential functions. The results of the study serve to provide the community with important information they can use in conducting their buying and selling activities.