This study presents the unique dichotomous role of social media, which we conceptualise as its competing-complementarity. Using the competing-complementarity phenomenon as a guiding lens, we explore the fusion of social media and business functions as core elements of a digital business strategy of a firm. The phenomenon shows a dual impact. Complementarity explains how digital technologies and business functions are synchronised and form the digital business strategy while competing shows how the digital business strategy is susceptible to destabilization. In the process, we describe 8 unique characteristics of a complementing social media and 4 characteristics of a competing social media, through which we derive two key triggers of competing-complementarity (1) key external trends, and (2) key organisational transferals. The conceptual idea of competingcomplementarity driving digital business strategy as well as its destabilization is illustrated through the technology S-Curve, which also shows the evolutionary nature of digital business strategies driven by digital technologies. This represents a strong theoretical view of technological progression in a firm. When key organizational shifts and external trends impact social media, it reflects both, positive and negative outcomes.