Abstract
With the development of the Internet, the telecommunication market has seen a rapid shift from voice-based services to data-based services. Relationships of substitutability and complementarity have emerged among communications technology services such as Internet service, mobile phone service and fixed telephone service. The article analyses the diffusion patterns of communication services in different continents. A modified logistic growth model is estimated using panel data for the years 1975–2004. The research forms a valuable framework for forecasting demand for new services based on the diffusion of incumbent services and can inform strategies for entering the communications network industry.