Social-Media-Based Learning (SMBL) is the use of social-media-based platforms, such as Twitter, Google Plus, Facebook, and YouTube, for learning purposes. It facilitates interactive, participative, and cooperative learning among people in real time. This study aimed to determine the factors influencing SMBL in higher education institutions and to assess the mediating effect of trust on the target platform. To this end, we developed a model by combining the theoretical constructs of the unified theory of acceptance and use of technology theory with the concept of "trust." We used the structural equation modeling method (partial least squares analysis) to analyze data collected using an online survey of 300 participants that included university students and faculties of higher education institutions in Bangladesh. In addition, we used importance-performance map analysis to determine constructs having relatively high importance, but showing relatively low performance. The study revealed that performance expectancy, effort expectancy, social influence, and facility conditions have a significant impact on social media usage intention. Furthermore, trust partially mediates the direct impact of performance expectancy, effort expectancy, and social influence on social media usage intention. The findings imply that trust has higher importance but relatively low performance.