Seiberg duality in supersymmetric gauge theories is the claim that two different theories describe the same physics in the infrared limit. However, one cannot easily work out physical quantities in strongly coupled theories and hence it has been difficult to compare the physics of the electric and magnetic theories. In order to gain more insight into the equivalence of two theories, we study the 'e+e' cross sections into 'hadrons' for both theories in the superconformal window. We describe a technique which allows us to compute the cross sections exactly in the infrared limit. They are indeed equal in the low-energy limit and the equality is guaranteed because of the anomaly matching condition. The ultraviolet behavior of the total 'e+e' cross section is different for the two theories. We comment on proposed nonsupersymmetric dualities. We also analyze the agreement of the 'yy' and 'WW' scattering amplitudes in both theories, and in particular try to understand if their equivalence can be explained by the anomaly matching condition.