  We investigate the sampling and dipole convergence properties of flux-limited
samples of mock X-ray clusters in relation to their underlying ``parent''
cluster distribution. To this purpose, we resort to numerical simulations of
the cluster distribution and extract samples resembling the main observational
features of X-ray selected cluster samples. The flux-limited samples, being
quite sparse, underestimate the amplitude of the ``parent'' cluster dipole by
approximately 15 per cent on average for Local Group-like observers. However,
the general shape of their dipole amplitude profiles are in relatively good
agreement. We also calculate the expected contribution of clusters, selected
according to the relevant criteria, to the soft (0.1-2.4 keV) extragalactic
X-ray background, using the ESO Key Project X-ray luminosity function, assuming
a flat universe with vanishing cosmological constant. We obtain a value of
about 10 per cent of the observed XRB flux.
