||The impacts of help-seeking (HS) on purchase decisions associated with social media websites (SMWs) are deemed powerful given the enormous popularity of social media and growth of social commerce. This research explores HS on SMWs and empirically investigates how it influences users’ decision performance. Utilizing the heuristic-systematic model (HSM), media system dependency (MSD) theory, and tangibility theory, in addition to HS logics, the research proposes a theoretical model incorporating both a MSD path and tangibility path for gauging purchase decision on SMWs. Two HS logics—dependent and autonomous—moderate the relationships between gratification, perceived diagnosticity, and decision performance. Data collected from 629 users of SMWs supported all of our hypotheses. Practitioners can benefit from the findings by more fully understanding the prospective value of diverse supports afforded by SMWs and constructing new guidelines to design more effective mechanisms that help consumers.