  We propose a model for the World Wide Web graph that couples the topological
growth with the traffic's dynamical evolution. The model is based on a simple
traffic-driven dynamics and generates weighted directed graphs exhibiting the
statistical properties observed in the Web. In particular, the model yields a
non-trivial time evolution of vertices and heavy-tail distributions for the
topological and traffic properties. The generated graphs exhibit a complex
architecture with a hierarchy of cohesiveness levels similar to those observed
in the analysis of real data.
