The Active Bat system provides the ability to locate users and equipment with a high degree of accuracy and coverage. Despite this, participation is low. We are concerned that this is symptomatic of a fundamental problem in location-aware computing; specifically the lack of understanding about which applications are useful and what factors motivate people to use them. In this paper we provide a retrospective analysis of Bat system usage grounded in game theory. We have analysed the needs of

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... le within the coverage area, and used this to motivate a set of highly targeted location-aware applications which we believe are compelling enough for individuals to induce a gradual increase in participation. This carrot approach has been successful and has increased the number of people who wear their Bat. Finally, this paper provides a critique of our experience with the Active Bat system. We suggest a number of refinements that should be considered by developers of future location systems.