Complex particles have been formed by the electrostatic association of protonated polystyrene-b-poly(2-vinylpyridine) (PS-b-PVPH+) micelles with sodium poly(styrenesulfonate) (PSS-Na+), ail at pH 1. Light scattering demonstrates that there is a large mass excess of PSS- associated with each PS-b-PVPH+ micelle (the molecular weight increases by factors of 5-6), even in the limit that the weight ratio of the micelle to PSS-Na+ is very low, thereby avoiding bridged structures. This system is an example of charge and mass overcompensation, but to a much greater extent than usual. Surprisingly the effect of the molecular weight of the PSS-Naf is minor. We believe that it is the flexible polymer micelle corona that permits such a large degree of mass and charge overcompensation because the linear PSS-Na+ can penetrate the micelle corona and adopt a convoluted local conformation with many loops or points of grafting attachment. While these particles are stable with respect to storage, they do not seem to be stable to centrifugation or filtration. The former instability is ascribed to the concentrating of the complex micelle as centrifugation proceeds while the latter suggests these particles are not stable with respect to shear.