There was a brief moment of hope that the industry would find a way to standardize a unit of measurement in network interconnection deals. Last year Level 3 Communications Inc., was working on a concept called bit-mile peering, which calculated traffic exchange costs based on both data volume and distance traveled. The company hasn’t abandoned the concept, but it doesn’t appear to have gotten much traction with ISPs either.
Source: Interconnection Deals: Parsing the Data | Light Reading