Swap and Save: How a Button Shapes Lasting Online Grocery Shopping Behavior

A well-documented phenomenon in the literature is that consumers exhibit persistence in their choices. Using data from the mineral water category on a price comparison platform that delivers real-time prompts of cheaper alternatives through "swap and save" buttons, this study examines whether and how these prompts influence persistent product choices in online grocery shopping. The findings reveal that shoppers who switched to an alternative product after receiving a prompt were 23.7 percentage points more likely to select that alternative product in subsequent visits, with this effect lasting for up to 10 shopping trips. Our analysis suggests that this sustained impact is driven not by long-term cost savings but by product discovery enabled through these real-time prompts.