The scope of this article is to explore the transaction profitability of frequent and sporadic buyers in the e-commerce arena. Evidence in relationship marketing literature stressing the impact of purchase frequency on customer transaction profitability as well as recent academic research challenging this approach and pointing out the importance of sporadic clients is analyzed and presented. A single case study research methodology was chosen for this article due to the exploratory facets associated with the subject and the industry under investigation. In order to gather relevant input to carry out this research, one of the largest retailing groups in Brazil was investigated. Conclusions are drawn showing that greater frequency of purchases does not necessarily translate into increased customer transaction profitability. Implications are presented, enabling practitioners and academics to grasp fully the real value of customers — both frequent and sporadic buyers — in order to develop coherent approaches for dealing with them adequately.