  The power carried by the jet of blazars is large, compared to the luminosity
produced by their accretion disk, and is probably in the form of kinetic energy
of a normal electron-proton plasma. The Poynting flux is modest, as suggested
by the inconspicuous synchrotron luminosity when compared to the high energy
(hard X-rays and gamma-ray) one, assumed to be produced by the inverse Compton
process. It is suggested that the jet power and the SED (Spectral Energy
Distribution) of its emission are linked to the mass of the black hole M and
the accretion rate dot M. This corresponds to a new "blazar sequence" based on
M and dot M instead of only the observed blazar luminosity. These ideas can be
tested quite easily once the AGILE and especially the GLAST satellite
observations, coupled with information in the optical/X-ray band from Swift,
will allow the knowledge of the entire SED of hundreds blazars.
