A general model for the marketing of seasonal products

We discuss a general model for the marketing of seasonal products, namely products for which the time intervals devoted to production and sales are distinct. The firm can advertise the product, thus affecting the sales in two different ways, namely directly (customers effect) and indirectly (retailers effect). A two-dimensional goodwill variable represents the (retailer, customers)-advertising capital stock. The dynamics of the system in the sales interval only is analysed, in order to determine the levels of goodwill and inventory at the beginning of such time interval and the subsequent advertising policy, so as to maximize the discounted net profit.