Deeply virtual Compton scattering on hadrons is used as a tool to probe the structure of the target particles and in this way we learn about QCD in the non-perturbative regime. The standard analysis relies on factorization of the amplitude in a hard-scattering part that can be treated in perturbation theory, and a non-perturbative 'soft' part. It is well known that this factorization is not exact; its accuracy depends on the kinematics of the scattering process, in particular the virtuality of the photon being absorbed by the hadrons. We study this dependence in a simple model, that allows for an exact treatment of the soft part. In the talk the question at what values of the virtuality factorization becomes accurate will be addressed.