The sharing economy, which is considered a better way of utilizing existing resources, is associated with positive effects not only on the financial aspects of sustainability but also on its environmental and social dimensions. But is this true? Previous research has typically discussed either the positive or negative aspects of the sharing business model in specific contexts. This study adopts a dual perspective regarding the sustainability of sharing business models by critically analyzing the relationship between sharing business models and sustainability. Building on the resource-based view of the firm and practice theory, the current research develops a conceptual framework for evaluating the sustainability of sharing business models at the level of the individual, the firm, and society. Our proposed dual-process model suggests that two competing processes contribute to sustainability. The study's conceptual model and propositions advance theory and provide a research agenda for future empirical studies. This research also provides valuable guidance to managers and policymakers regarding the sustainability of sharing business models, which can inform the business model innovation process.