  We discuss string scale unification facilitated by exotic matter with masses
at intermediate scales, between the observable sector supersymmetry breaking
scale and the string scale. We point out a mechanism by which string scale
unification may occur while producing a (lower) virtual unification scale
independent of the location of the intermediate scale and the value of the
string coupling. The apparent unification obtained by extrapolating low energy
gauge couplings is not accidental when this mechanism is invoked; virtual
unification is robust.
