  In this paper we study the problem of content placement in a cache network.
We consider a network where routing of requests is based on random walks.
Content placement is done using a novel mechanism referred to as reinforced
counters. To each content we associate a counter, which is incremented every
time the content is requested, and which is decremented at a fixed rate. We
model and analyze this mechanism, tuning its parameters so as to achieve
desired performance goals for a single cache or for a cache network. We also
show that the optimal static content placement, without reinforced counters, is
NP hard under different design goals.
