There is provided an apparatus and method for a webshop such that the products shown to a customer are related to the purchasing habits of the customer. A control unit is arranged to communicate with a product information database, a product category database and a customer purchase history database. The control unit includes a product categorising unit arranged to generate at least one product category based on product information in the product information database and to store the at least one generated product category in the product category database. A calculating unit is arranged to calculate a probability of a customer being an underbuyer/overbuyer of a type of product based on the customer's purchase history stored in the customer purchase history database and the at least one product category from the product category database.