The exercise of power sources is central to the management of channel relations. To help researchers and managers to improve the effectiveness of their efforts, available empirical articles on the exercise of power sources from the period 1974-2014 are synthesized in a meta-analysis. The relationships between different exercised channel powers are generalized. Coercive and legitimate powers are strongly correlated, whilst there are strong relationships among reward, referent, expert, and information powers. Thus, the research proposes that the most reasonable classification of the exercise of channel powers is its dichotomization into coercive power (i.e. coercive and legitimate) and non-coercive power (i.e. reward, referent, expert, and information).