Many product-customization systems enable consumers to obtain input from their peers during the customization process. The design characteristics of these customization systems vary significantly, and some systems provide consumers with the opportunity to receive peer input only privately (i.e., unobservable to fellow consumers) while others allow consumers to receive peer input publicly (i.e., observable to other consumers). Building on prior research on thinking styles and social impact theory, the current work examines the interplay between user, social network, and system design characteristics in social product-customization systems as drivers of whether consumers conform to input received from others on their customized products and of their evaluation of these products. Evidence from one field study and four experiments shows that consumers with more holistic (vs. analytic) thinking styles make more conforming product modifications when receiving public rather than private peer input, and this greater conformity to peer input boosts (vs. diminishes) consumers’ evaluation of customized products when they feel close (vs. distant) to input providers. These findings offer novel insights into how the design of social product-customization systems affects consumers’ evaluation of customized products.