  We present a simple model for growing up and depletion of parties due to the
permanent communication between the participants of the events. Because of the
rapid exchange of information, everybody is able to evaluate its own and and
all other parties by means of the list of its friends. Therefore the number of
participants at different parties can be changed incessantly. Depending on the
deepness of the social contacts, which will be characterized by a parameter
$\alpha $, a stable distribution of party members emerges. At a critical
$\alpha_c$ an abrupt depletion of almost all parties is observed and as the
consequence all the peoples are assembled at a single party. The model is based
on a hierarchical social network. The probability that a certain person is
contacted to another one depends on the social distance introduced within the
network and homophily parameter $\alpha $.

Physics and Society