Smart urban tourism destinations with IoT-based devices and applications are the future of world tourism. This study identifies core factors of sustainable IoT-based interactive marketing influencing urban tourism destinations. The study adopts a systematic approach with two sides of the tourism system including supply-side and demand-side. The findings showed that factors including smart tourism ecosystems, new business approach employing multi-sided platforms, intra-organizational participative through network-based model, big data analysis, green marketing campaigns, enhance tourists' environmental knowledge and awareness, and smart CRM were determined as core factors on the use of IoT in sustainable interactive marketing. On demand side, based on the findings, perceived usefulness, perceived ease of use, trust, social influence, cyber-resilience, and perceived privacy have been determined as core indicators on the use of IoT in sustainable smart interactive marketing.