Estelle van Tonder is an Associate Professor at the North-West University in South Africa where she teaches Retail Management and Strategic Marketing. She has a doctorate degree in Marketing Management and her research has been published in journals such as The International Review of Retail, Distribution and Consumer Research, European Business Review, The Service Industries Journal and the International Journal of Bank Marketing. Her main research fields are relationship marketing, consumer helping behaviour from a citizenship perspective and informal knowledge sharing behaviour among consumers.