Under the term “digital health,” advanced medical technologies, disruptive innovations, and digital communication have gradually become inseparable from providing best practice healthcare. With the increasing importance of health and wellness tourism, thermalism has become a very competitive product wanted by tourists who need treatments that are not available in their country due to lack of availability or because they are quite expensive. Since tourism is integrated in the services sector, a set of relational marketing strategies can be applied to establish and maintain relationships with tourists. Therefore, it is important to understand how relational marketing can improve health and wellness tourism. Based on a combination of theoretical and practical research, this chapter explores the dynamic system and mechanism of innovation and development of digital relational marketing strategies in specific contexts of tourism (i.e., health and wellness tourism) considering cross-border. From an interdisciplinary perspective, the chapter presents insights for digital relationship marketing and tourism (health and well-being) and for economic development.