Effect of core and peripheral product line extensions on overall product line revenue

Purpose Firms often use upward product line extensions to achieve gains in brand evaluations and in overall demand. Despite the prevalence of such extensions, previous research has provided little guidance about how upward line extensions influence overall revenue when they are launched as a core product as opposed to a peripheral product. The purpose of this study is to fill this research gap. Design/methodology/approach Using data from the quick service restaurant industry, this study looks at the effects of upwardly extended core and peripheral products on product line revenue. The empirical study uses a quasi-experiment to compare customer purchases across the pre- and post-launch of upward line extensions. Findings The results of this study reveal that launching core and peripheral products as upward line extensions can each increase total product line revenue. In addition, findings illustrate that as compared to a core launch, this total product line revenue increase is substantially higher in the case of a peripheral launch. Research limitations/implications First, the estimated model does not include supply availability and competition. Second, the data span only six months and this restriction prohibits us from investigating alternative sources of the causal effect. Third, the empirical setting in this study is limited to financial data in the quick service restaurant industry as a proxy of actual behavior. Finally, given that customers are not randomly assigned to treatment and control groups, the author is unable to definitively rule out the effect of unobservable attributes. Practical implications The findings suggest that firms should prioritize peripheral upward line extensions but use both types considering resource constraints (cost and human resources) and strategic importance to the firm. Originality/value This study bolsters the extant literature related to upward product line extensions by providing an empirical framework that evaluates the causal effect of upward line extension on total revenue, using field data in a real-life setting (as opposed to survey or lab experiment data) and actual firm revenue (as opposed to a perceptual outcome measure such as behavioral intentions). In addition, findings contribute to the new product development literature.