This study explores the dynamics of the Korean Mobile Virtual Network Operator (MVNO) industry, focusing on the strategic decisions small and medium-sized enterprises (SMEs) face between efficient management and technological advancement. In a sector dominated by subsidiaries of Mobile Network Operators (MNOs), SMEs encounter unique challenges in competing effectively. Using Data Envelopment Analysis (DEA), Malmquist Productivity Index (MPI), and Importance-Performance Analysis (IPA), this study evaluates the efficiencies and productivity changes of nine MVNO companies. The results indicate that while operational efficiency does not directly correlate with increased market revenue, advanced technology offers a significant advantage, boosting both productivity and customer satisfaction. Notably, technological advancements were found to have a more substantial impact on market competitiveness than efficient management. Our study suggests that SME MVNOs should prioritize technological innovations, such as data speed and service quality, to strengthen their market position. Our research also provides valuable insights into enhancing the competitiveness of Korean MVNOs and offers practical guidance for business strategies within the telecommunications sector.