The solubilization power of a detergent, defined as the moles of solute dissolved in the micellar pseudophase at saturation per mole of micellized detergent, is often employed to characterize the affinity of a given detergent micelle for the solute of interest. As shown here, however, the solubilizing power is the product of two equilibrium constants, one of which expresses the intrinsic solute-micelle affinity and the other the saturation solubility of the solute in the intermicellar aqueous phase. Consequently, for relatively water insoluble solutes, the maximum extent of solubilization can be dictated by the saturation of the aqueous phase rather than by saturation of the micellar phase itself, with the result that micellar solutions can saturate even when a substantial fraction of the micelles have no solute dissolved in them tat occupation numbers much less than unity).