Network coding is an elegant and novel technique introduced at the turn of the millennium to improve network throughput and performance. Its power comes from allowing network nodes to combine and process different incoming information streams. It is widely believed that potential benefits of network coding are huge, in particular in terms of throughput and security. By using techniques of combinatorial optimization and occupancy models, this talk will examine whether such beliefs are generally justified, and quantify coding benefits for certain network topologies and traffic scenarios.