We introduce a traffic demand aware cost model for the creation of overlay routing networks. We investigate the effects on the created network topologies when the traffic demand between nodes is considered. The resulting network topologies often differ dramatically from topologies formed when traffic demand between nodes is not weighed. We found that the global network characteristics were changed as well as individual node placement in the topology. Our results clearly show that the overlay network topology is adapted to reflect the underlying traffic demand distribution. We conclude that overlay network topologies formed using a traffic demand aware cost model are better suited to carry the traffic demand between nodes.