How Do Shoppers Respond to Noisy Signals on Price Changes? Evidence from a Field Experiment in Online Supermarket Shopping*

What is the effect on the demand for both discounted and nondiscounted products, when promotional material informs shoppers that some product categories feature discounts? We address this question by conducting a field experiment on a website for online grocery shopping. We find that shoppers who had purchased in a certain food category prior to the experiment responded to noisy promotional information by purchasing items in the discounted category that they had already purchased in the past, regardless of whether the item purchased was currently discounted. Our results suggest that coarse information on discounts increases both consumer spending and seller revenue.