Localizing BitTorrent traffic within an ISP in order to avoid excessive and often times unnecessary transit costs has recently received a lot of attention. In this work we attempt to answer yet unanswered questions like “what are the boundaries of win-win outcomes for both ISPs and users from locality?”, “what does the tradeoff between ISPs and users look like?”, and “are some ISPs more in need of locality biasing than others?”. Categories and Subject Descriptors: H.4.3 Information Systems Applications: Communications Applications. General Terms: Measurement, Performance.