  We study different mechanisms of gossip propagation on several network
topologies and introduce a new network property, the "spread factor",
describing the fraction of neighbors that get to know the gossip. We postulate
that for scale-free networks the spreading time grows logarithmically with the
degree of the victim and prove this statement for the case of the Apollonian
network. Applying our concepts to real data from an American school survey, we
confirm the logarithmic law and disclose that there exists an ideal number of
acquaintances minimizing the fraction attained by the gossip. The similarity
between the school survey and scale-free networks remains even for cases when
gossip propagation only occurs with some probability $q<1$. The spreading times
follow an exponential distribution that can also be calculated analytically for
the Apollonian network. When gossip also spreads through strangers the
situation changes substantially: the spreading time becomes a constant and
there exists no ideal degree of connectivity anymore.
