This thesis investigates the impact of online social influence on consumer behaviour, specifically within the context of online reviews. It examines how review volume and user-generated photos affect consumer evaluations and decision-making. In Chapter 2, I introduce a novel phenomenon, the N-effect, which explores how opinion volume influences the content of online evaluations. I find that as the number of opinions increases, the content becomes more emotional and less analytical. In Chapter 3, I investigate the role of user-generated photos in shaping purchase intentions. This research demonstrates that photos can enhance review helpfulness, even when they lack diagnostic information. This effect is driven by the confidence signalled by the reviewer when posting a review with a photo, which is later assimilated by readers, leading to increased perceived helpfulness and purchase likelihood.
This thesis makes several theoretical and practical contributions to the literature on human interaction with technology. Theoretically, it expands our understanding of online social influence by examining the dynamics of online opinion expression and content. I contribute to the literature on group size by demonstrating how responsibility may be lost in online contexts. Furthermore, the findings provide insights into the social influence of photos on viewers and the role of pseudo-evidence in shaping beliefs and attitudes.
From a practical standpoint, this research offers valuable insights for online platform managers and marketers on interpreting and using consumer-written reviews. Overall, this thesis contributes to the existing literature on online social influence and provides insights for businesses to improve communication and interpretation with consumers by better understanding and leveraging online reviews and opinions.Open Acces
