  We apply a physical based model to describe the clothes fashion market. Every
time a new outlet appears on the market, it can invade the market under certain
specific conditions. Hence, the "old'' outlet can be completely dominated and
disappears. Each creator competes for a finite population of agents. Fashion
phenomena are shown to result from a collective phenomenon produced by local
individual imitation effects. We assume that, in each step of the imitation
process, agents only interact with a subset rather than with the whole set of
agents. People are actually more likely to influence (and be influenced by)
their close ''neighbours''. Accordingly we discuss which strategy is best
fitted for new producers when people are either simply organised into anonymous
reference groups or when they are organised in social groups hierarchically
ordered. While counterfeits are shown to reinforce the first strategy, creating
social leaders can permit to avoid them.
