Why we buy what others buy: The role of product popularity in consumer decision making

Consumers often look at the behaviour of others to inform their own choices. As a result, many of consumers’ daily decisions are socially influenced. This thesis addresses the question of why consumers choose what others have chosen before. Specifically, the thesis focuses on the effect of product popularity (i.e., the widespread adoption of a single product) on consumer choice. The overall aim is to use the distinction between informational and normative social influence to examine how a single popularity cue can influence consumer choices, and to assess the potential of product popularity to positively influence consumer well-being. Chapter 1 lays the foundation for the studies and outlines the general objectives. Chapter 2 explores the neurological and psychological mechanisms that underlie the effects of popularity. The results extend insights on the distinction between normative and informational social influences. The study confirms the existence of two distinct patterns on a neurological level, reflected by different brain regions, and on a psychological level, reflected by different inferences. The results extend insights on the distinction between normative and informational social influences and offers the first evidence of the duality of the value that consumers may ascribe to popular products. Chapter 3 further examines the inferences that consumers may draw from popularity from the perspective of consumer (lay) naive theories. The chapter identifies novel inferential mechanisms that provide further insights into why popularity drives choice. For normative social influence, the chapter identifies the inferential mechanism of societal value that operates next to the mechanism of social value (i.e., social approval). For informational social influence, the chapter provides an account of the inferential mechanism of certainty about quality that operates next to inferences of quality. The results of five experiments demonstrate the consistency with which consumers make the inference about certainty. The concept of certainty about quality represents the confidence interval surrounding perceived quality. As such, it can be considered a complementary mechanism that further aids in unravelling the value that consumers may ascribe to popular products. Chapter 4 explores the potential for product popularity to stimulate healthy food choices and specifically focusses on stimulating the choice for healthful alternatives that have a taste disadvantage as a result of trimmed down nutrient profiles (low in fat, sugar or salt). The study builds on the premise that the value ascribed to popularity reflects functional value and accommodates concerns about quality. This is tested in a virtual, 3D representation of a local supermarket. The results show that consumers are more likely to choose light products when these are accompanied by a popularity cue. The findings offer support for using product popularity to stimulate healthful consumer choices. Finally, the chapter 5 provides an overview of the main findings of the thesis and discusses implications for theory and practice. Overall, this thesis demonstrates the duality of the value that consumers may ascribe to popular products. By drawing on insights from different scientific disciplines, and combining different research methods, the thesis confirms that popularity offers consumers the chance to assess multiple consumption values at once.