In this paper we ask how an extended service model is developed over time in the relationship between buyer and seller in the trucking industry.  Extended service models following a service-dominant logic rather than a product-dominant logic are becoming increasingly important in many industries.  Here we report on the initial stages of a large study on the use and development of extended service models in the Swedish market for trucks.  We see considerable promise in studying the development of the concept over time in the interaction between customer and provider.