To purchase or to remove? Online shopping cart warning pop-up messages can polarize liking and purchase intention

Online companies, such as eBay and Taobao, often set limits on the maximum number of items placed in the shopping cart. When the number of items added exceeds the limit, a warning message would pop up, asking consumers to clean, remove, or purchase first. Extant research on online shopping cart abandonment examines the various factors that can lead to shopping cart abandonment but does not explore the effect of such warning messages on attitudes and purchase intention. Through five studies (i.e., Studies 1, 2A, 2B, 3, and 4), we show that reminding consumers to clean items in their online shopping carts can polarize liking and purchase intention towards the most-favorite and least-favorite items. Furthermore, we find that reminding consumers to remove items (rather than to purchase them) magnifies the polarization. Consumers' anticipated regret mediates the interactive effect of warning message type and preference ranking on liking and purchase intention. In addition, the scarcity or abundance of product supply moderates the interaction effect of shopping cart warning message type and preference ranking on liking and purchase intention. Implications for both theories and practices are discussed.