The paper is an outcome of a study on the factors of the emerging e-commerce adoption and usage in the mainstream grocery supermarket sector in South Africa. A qualitative, interpretive method using multiple case studies, together with a purposive method of sampling was used. To improve generalisability, more than one leading chain store: Pick’n Pay, and Woolworths were selected as case studies. Individual customers were also interviewed to learn of their experiences with, and preferences of e-commerce in the sector. The activity theory (AT) was used to contextualise e-commerce as a work activity. The theory offers a holistic lens for retailers, banks, customers and even researchers to understand, investigate and approach factors of e-commerce usage. The leading assumptions of a theoretical framework was that e-commerce as an activity system is not an automatic but a deliberate phenomenon that is driven by goals of the retailer and the needs of the customer. Related activities include the presence of facilities among local communities and awareness (marketing) efforts by service providers. Findings suggest that e-commerce offerings by retail supermarkets are not well known by most customers, hence usage is limited. Among the few that use it, it is found to be time-efficient and convenient. Nevertheless, lack of access to e-payment facilities and fear of cyber crime remain a threat to widespread usage. Thus, banks, retail supermarkets and the educational sector need to educate the public on e-commerce and security consciousness. Finally, e-commerce facilities should spread beyond boundaries major cities if its conveniences are to be within reach of the majority. Though sample size was adequate for the exploratory purposes of this study, it would have been preferable to interview the whole South African consumer population, an exercise was beyond the capacity of the project, but recommendable for future studies.