This paper is based on a relationship marketing perspective and points out the evolutional nature of place marketing networks. According to this framework place marketing is defined as an approach for the creation and further consolidation of a relationship network between Authorities that manage territory elements (Local Government Authorities or LGA) and place users (specifically business investors). Furthermore the authors identify the existence of a temporal evolution of place marketing network articulated in the following phases: 1) awareness, 2) pre-network informal network, 3) formal network, 4) growth and 5) sustainment-demise-rebirth-decline-renaissance. The recognition of the existence of a territorial network evolution should push the LGA and the other promoters of territorial networks to plan and act marketing strategies (to attract investments) considering the evolutional phase in act. On the empirical side the paper analyzes the Province of Florence place marketing features. Particularly the authors concentrate their interest in: a) the Florentine place marketing network evolutional pattern; b) the marketing strategies and policies developed for the business segment by the Province of Florence; c) the interactive-collaborative quality of the place marketing activities developed by the Province towards businesses clustered in the Florentine area or interested in creating business relations with the territory. The method used in this research is founded on the qualitative case study method. From both a theoretical and a managerial point of view, this paper finally tries to provide some items useful to develop a method for evaluating place marketing actions, specifically those functional to attract investments. Keywords: Relationship Marketing, Place Marketing, Local Government Authorities, Place Marketing Network, Network Evolution, Investment Attraction.