With the explosive growth of the Internet in the 1990s, the scalability of current technologies has become a significant issue. The current version of Internet Protocol version 4 (IPv4) apart from some other drawbacks limits the number of available IP addresses. The next version of IP, version 6 (IPv6), provides a comprehensive solution to several limitations of current Internet technology. However, to date Ipv6 has not been widely adopted. Traditional diffusion theory suggests five factors that effect adoption of new technologies. Economists who suggest network externalities and economic returns as additional factors provide an alternative perspective. This paper discusses these factors and how they are likely to influence the uptake of IPv6 by Internet Service Providers.