In recent years the web-based Relationship Marketing (RM) has been receiving a great attention from e-marketing perspective. The RM is evolved as a contemporary marketing initiative, which can be applied to all types of industries. Concurrently, because of the advancement of the Information Technology, web-based promotion and market offering are considered as dominating business development tool. From this context, five grown sporting cases have been analysed to realise how web-based promotion influences RM to develop a sustainable growth model, where the cases have been utilising the RM and web-based promotion lucratively to attain and retain the key stakeholders to sustain their growth. Following the initial literature review, the websites of the cases have been scrutinised thoroughly as data collection tool. Nineteen RM indicators are identified as different RM perspectives. The cases are positioning web-based promotions and offerings underlying these RM indicators as a combined promotional effort to enhance competitive advantage. From the case analysis, the concept of stakeholder causal scope is evolved as identical with this combined promotional effort, as well as proportionate with at least one of the four identified growth strategies. Finally, the RM centred ‘Sustainable Growth Model’ has been developed through the synthesis of the impact of the web-based RM indicator focused combined promotional effort of the cases on the associated stakeholder causal scopes and their relevancy with the growth strategies. Reinforcing the model is established significantly for marketers in various industries to enhance competitive advantage aiming to sustain organisational growth.