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Dark matter annihilation in so-called ``spikes'' near black holes is believedto be an important method of indirect dark matter detection. In the case ofcircular particle orbits, the density profile of dark matter has a plateau atsmall radii, the maximal density being limited by the annihilationcross-section. However, in the general case of arbitrary velocity anisotropythe situation is different. Particulary, for isotropic velocity distributionthe density profile cannot be shallower than r^{-1/2} in the very centre.Indeed, a detailed study reveals that in many cases the term ``annihilationplateau'' is misleading, as the density actually continues to rise towardssmall radii and forms a weak cusp, rho ~ r^{-(beta+1/2)}, where beta is theanisotropy coefficient. The annihilation flux, however, does not change much inthe latter case, if averaged over an area larger than the annihilation radius.

Dark matter annihilation near a black hole: plateau vs. weak cusp