  We introduce a non-Gaussian model of structure formation, and show how it
produces surprising sampling effects on the estimation of the CMB power
spectrum. Estimates of the average power spectrum based on small sky patches
produce qualitatively different results from patch to patch, and vary also with
the patch size. For instance a system of secondary Doppler peaks is observed in
small enough patches, but at different positions in different patches. However,
no secondary Doppler peaks are observed in large sky patches. These effects
question usual methods of power spectrum estimation, and techniques like
bootstrapping. The non-Gaussianity of this model fails to be detected by
standard tests.
