This article shows how a town that wants to attract business investment, or the developer of a leisure park who wants to find out more about his clientele, can analyse the power of attraction of his image or project before going ahead with his investment plans. Depending on the cases described here, this research may entail either international or simply local investigation. Preferably, it should be undertaken at the outset of a project, at the moment of conception, so that the project can be adjusted in response to interaction between the client company and the market research firm, as the latter gradually learns more about the market being studied. In any case, territorial marketing - adapted in this instance to the leisure market - requires the study of a wide range of publics, using a qualitative approach. This may subsequently be supplemented by quantitative research where the need arises to estimate probabilities as to the potential clientele prior to the project's launch. The surveys presented here, i.e. for the Vichy Beauty Centre, the La Defense Activities Scheme, or the promoting the economic development of Marseilles, allowed the clients concerned to refine their projects (in some cases extensively) and to devise appropriate advertising, all before embarking on their investment programmes. These surveys enabled them to adjust their responses to the demands identified, and to rank their targets in order of priority. In the case of Vichy, the project's developers were persuaded to transform their initial concept. Advertising themes were supplied, which led to a harmonization of the entire project down to the decoration of the different sites. Indeed, the plan for the town as a whole was modified as a result. In the case of Marseilles, the study yielded a precise picture of the city's image deficit, which then served as a starting point for reconstruction based on types of action and communication better suited to the target publics.