Most cars carry one person and are used for less than one hour per day. A more economically rational approach would be to use vehicles more intensively. Carsharing, in which a group of people pay a subscription plus a per-use fee, is one such strategy. Smart carsharing employs advanced technology to facilitate tracking, billing, and system management. CarLink, a smart carsharing system, was deployed in the San Francisco Bay Area for ten months in 1999 to test this concept. This paper describes the CarLink economic data, and through scenario analysis, identifies several market conditions in which carsharing could become more economically viable. Our study found that CarLink could be sustainable when there is a strong cooperation with local businesses, higher user fees are generated, and technology and management costs are lowered.