  We argue that the exciton scenario for the magnetic resonance in the cuprate
superconductors yields a small spectral weight of the resonance, in agreement
with experiment. We show that the small weight is related to its concentration
in a small region of momentum and energy. Despite this, we find that a large
fermionic self-energy can indeed be generated by a resonance with such
properties, i.e., the scattering from the resonance substantially affects the
electronic properties of the cuprates below $T_c$.
