This paper reports on research carried out in 1999-2001 on the use of e-Business applications in ERP-based organisations. Multiple structured interviews were used to collect data on ten established organisations from a diverse range of industries. The findings are analysed according to the level of sophistication of e-Business models and their transformational impact on the organisation. Early adopters of e-Business show a trend towards cost reductions and administrative efficiencies from procurement and self-service applications used by customers and employees. More mature users focus on strategic advantage and generate this through an evolutionary model of organisational change. A complex case study of e-Business integration with a global supplier and their corporate customers is analysed to identify specific stages of benefits accrual through the e-Business transformation process. Collectively the set of case studies is used to demonstrate the increased benefits derived from an e-Business architecture based on a network of ERP enabled organisations.