The author applies a perturbation method to determine tidal deformations on a rotating, spherically asymmetric, visco-elastic, laterally heterogeneous and anisotropic Earth. He shows that the deviations from tides on a nonrotating spherical Earth are on the order of one per cent. This applies to the effects of rotation, ellipsoidal shape of the Earth, visco-elasticity, lateral heterogeneity and anisotropy in the mantle, separately. With respect to the effects of rotation and ellipticity he finds significant quantitative discrepancies from what was accepted so far. With respect to lateral heterogeneities in the mantle he argues that visco-elastic dispersion is responsible for a considerable amplification of the heterogeneities when moving from seismic to tidal frequencies. On this basis, he suggests tidal tomography as a new rool for studying temperature induced mantle anomalies with modern space techniques.