This paper uses the informational cascades perspectives to investigate how popularity of online service deals influences consumers’ reactions when (in)congruently presented with star rating evaluations. Previous research suggested that deal popularity and star rating are two common information cues representing past consumers’ online behavior that signal about online service quality potentially influencing prospective online consumers’ judgments and decision making (Flanagin et al. 2014; Kao et al. 2016). Hence this research aims to examine the conditions under which online deal popularity and star rating can effectively influence service quality evaluation and purchase intention. Using scenario-based experiments, we show how different combinations of information cues impact on the manner in which online deal popularity is used by consumers to shape service quality expectation and purchase intention. Findings indicate that congruency effect is highly influential when high deal popularity is paired with high star rating. Specifically, an informational cascade effect is activated by high deal popularity which overrides quality cue of low star rating. Accordingly, consumers’ service quality expectation and purchase intention are increased even when a low star rating is presented simultaneously with low star rating. Findings are useful to marketing strategists and e-retailers as they devise their online strategies, promotional campaigns and website design.