This case study examines consumer satisfaction levels and the number of complaints about the Trendyol brand posted on the sikayetvar.com website. This research presents the approach to analyzing the content of electronic complaints and categorizing them via the MAXQDA 2020 data analysis software. The results concur with published research that has observed that the lesser-known brands with low trade volume have high satisfaction levels and a small number of complaints, while well-known brands with high trade volume have high complaints and low satisfaction levels. Consumer dissatisfaction and negative brand image categories account for 54.76% of the complaints. In addition, it has been concluded that supply and cargo problems cause consumer dissatisfaction, and consumer dissatisfaction can negatively affect the brand image. In this context, the consumer-based equity of the brand may increase when the reproach and distrust of the brand decrease. Complaints of other electronic commerce companies can be also examined in prospective studies and their code-related maps can be created, compared, and partially combined in working towards producing a canonical theme, code, and exemplary expressions.