Strategic marketing ambidexterity (SMA), the blend of a firm's exploitation of existing competencies and exploration of future capabilities in strategic marketing activities, represents a dynamic capability that is vital in achieving superior performance. Given its criticality, the authors examine how firm antecedents and industry contexts affect the shift in a firm's SMA over time (movement in the blend of exploitation and exploration). In addition, the authors examine SMA's influence on firm financial outcomes, i.e., risk and return. Using data from 1999 to 2011 on publically traded firms, the authors show that firm maturity and slack (financial and strategic) are key determinants of SMA. Specifically, increased firm maturity and strategic slack result in a shift toward exploitation, whereas increased financial slack results in a shift toward exploration. Industry competitiveness moderates these effects. In terms of the financial performance implications of SMA, the authors find that shifts in SMA toward exploitation increase return, but they also increase firmidiosyncratic risk. The authors conclude with implications for theory and managerial practice.