This paper presents an empirical study on the use of a smartcard namely Octopus for micro e-payments in Hong Kong. The Octopus was initially designed to enable several public transport service providers such as subways, railways, buses and ferries to share a common platform for fare collection and settlement. Recently, it has been used to facilitate micro e-payments in selected service sectors. Individual customers can conveniently use a computerized smartcard for purchasing selected goods and services. A customer-oriented investigation suggests that perceived convenience of use, automatic add-value services, security, reliability, perceived ease of use, perceived usefulness and merchant support significantly influence continued use of the Octopus smartcard. Our empirical work provides useful information for developing sustainable smartcards for e-payments in different business environments.