When it comes to buying shoes, many online shoppers tend to order several products in different sizes to find the one that suits them, and then return the ones that don't fit. In this kind of situation, personalisation can reduce return rates and thus reduce costs, while at the same time increasing the level of customer satisfaction. When the products are added to the shopping cart, if two of the products are the same, a message pops up to help the shopper. This is to help show the customer how to choose their correct size so that they only order one pair.