The recent development of the more than two-decade-long research into reverse logistics has reflected the diverse economic, technological, environmental and societal concerns and challenges. The article presents an analysis between reverse logistics and process improvement and product design; more specifically it explores if and how the companies utilize reverse logistics and reverse flows (returned products and accompanied information flow) for improvement activities. To learn about customer expectation and experience with the product (i.e., to extend the customer knowledge) is an indirect benefit that reverse logistics can generate if managed properly. An exploratory (quantitative) analysis compares the companies that perceive themselves as successful and less successful in expanding customer knowledge by reverse logistics. Bivariate statistical methods were employed on ordinal (scale) data collected by interviews with the representatives of 148 companies in 2016 and 2017. The companies successful in gaining customer feedback as an indirect effect of revere logistics differ in their approach to innovations (the higher frequency of innovation, the strategic importance of reverse logistics, and in a higher formalization of management system). They also have the more developed knowledge management system at their disposal. Finally, the data show a positive relationship between reverse logistics- related feedback and general effectiveness. Several papers documented the link between knowledge management and effective reverse logistics; however, the empirical evidence about benefits of reverse logistics for (customer) knowledge management is scarce, and in this respect, the paper provides original insight. The results document that reverse flows and reverse logistics can generate more than just cost savings, which was perceived as its dominant function. More specifically, management of reverse flows can be a stable component of knowledge management system, the component that provides the companies with feedback about customer dissatisfaction (and other facts such as expectations, or user experience), which can be effectively employed in the innovation activities.