Estimating the value of passing trade from pedestrian density

We report empirical generalisations derived from mass observations of the Double Conversion model of shopping behaviour at rival comparison goods retailers and in fast food. Despite great differences in multiple conditions (footfall, time, image, location type, countries), these benchmarks closely predict customer conversion rates from observed pedestrian density. Store entry patterns conform to the Law of Double Jeopardy. Higher share brands in busier locations attract slightly more shoppers than expected, while closing ratios appear to be governed by the Law of Natural Monopoly. A simple model is offered and its uses demonstrated in a range of predictive and diagnostic managerial situations.