The aim of this research is to identify the expectations offered by small retail businesses towards local online selling platforms as an innovative tool to ensure their future and the urban sustainability. Based on the previous findings obtained from an analysis of trends, actors and marketplaces operating in the retail sector, sixty semi-structured in-depth interviews have been carried out to Spanish local retail managers and owners. Opportunities and risks faced by local online marketplaces are presented from the perspective of small retail stores. Different attitudes towards online shopping platforms have been identified depending on their size, presence and experience in the online world, which has allowed us to categorize local retail businesses in six groups. Despite the perceptual and attitudinal differences between them, it is concluded that merchants have assumed that the current and future business model goes through the digitalization of their businesses and the selling on e-commerce platforms. The coexistence of the e-marketplace and the physical stores, conducted by the same retailers, could have a positive effect on the urban sustainability: on the one hand, with the economic strengthening and renovation of the historical centers and, on the other, with the maintenance of the population and traditional social relationships.