Ecommerce is ideally suited to G2C interactions, however because Government is both conservative, and often chooses contractors that are expert in Government systems rather than ecommerce there have been a number of expensive failures and there are a large number of G2C ecommerce systems that have very poor usability. Generally Government is a monopoly so it does not have the competitive force that has driven the improvements in B2C ecommerce and is often behind B2B in functionality and roll out.
Government is still gradually adopting ecommerce, and the benefits are now well proven. However there is still a tendency to significantly over specify and pay resulting in overly complex ecommerce systems. A low cost ecommerce system ensures benefits, and allows the service to be promoted so that customers are aware that they can interact electronically.