Community-based social marketing is a relatively new approach in marketing which makes use of social networks within communities to disseminate marketing messages in a information campaign. Agent-based models can be used as a tool for exploring the sensitivity of such campaigns to the structure of social networks within target communities. We develop an agentbased model for a social marketing campaign within surrounding communities for ecotourism services in a wetland. As the revenues from ecotourism are used to fund the rehabilitation efforts in the wetland, the longterm sustainability of the wetland is dependent on the success of the marketing of the ecotourism services. We find that for a small world social structure the success of the social marketing campaign is highly dependent on the number of links between communities. The results suggest that the design of social marketing campaigns may need to take account of social networks between and within communities.