The tight connection found between the IR and the gamma-ray emission for the blazar population require a physical explanation. I will address and clarify this relation with the use of extensive MonteCarlo simulations. We found that it is possible to describe the peculiar IR colors of the gamma-ray emitting blazars, in terms of a curved non-thermal spectral shape. Although an additional component appears to be required in several cases to interpret the origin of the WISE Gamma-ray Strip.