This study examined how Plan B Media Public Company Limited became a leading Out-of-Home (OOH) media industry. Founded in 2005, Plan B began with classic OOH media. Then through the development of Bangkok, Plan B experienced fast growth and listed in the Stock Exchange of Thailand (SET) becoming one of the SET100 Group of companies. However, the OOH market had to adapt because of digitalization that has affected many industries. Therefore, Plan B strengthened its sustainability, partnership and engagement marketing strategies. Furthermore, the company has a positive relationship with key domestic players. Nevertheless, the company’s turning point was the partnership with VGI Global, a major OOH competitor in Thailand, who acquired an 18.59% stake in Plan B. This partnership called the “Bangkok Takeover” has a total value of more than 70% of the country’s OOH market. Another impacted strategy was engagement marketing, which differentiated the company from its core business with three potential contents: music marketing, sports marketing and Esports. The process began with the acquisition of BNK48, an idol group with an innovative revenue model, and as the official marketing supporter of the Football Association of Thailand (FAT) and Thai Premier League. These ventures led to new clients, a business ecosystem and sustainability of the revenue balance for Plan B’s business. In its overseas expansion, the company invested in nearby markets; such as, Singapore and Malaysia. Moreover, the ASEAN Economic Community (AEC) has provided major opportunities for Plan B’s future with the future lowering of the barriers for the OOH media industry. In conclusion, the case provided how the company has grown and highlighted past strategies that could be learned and analyzed from the framework and theory. Additionally, the future challenges of Plan B were described that would provide changes for the company’s sustainability and long-term goals.