Many SMEs still seem reluctant to accept the management of large datasets, which still appear to be too complex for them. However, our study reveals that the majority of small French car dealers are developing Big data and Smart data policies to improve the quality of their offers, the dynamism of their sales and their access to new opportunities. However, not every policy has the same effects on the development of their business. Whereas Big data improves all the components of SME development in a global, short-term and operational way, Smart data presents itself as a more targeted, prospective and strategic approach.