Changes within the air transport sector have required many European airports to either develop or expand their commercial activities. Strategies have included the expansion of retail space, a broadening of the tenant and merchandise mix and the development of a passenger segmentation strategy. This paper explores the efficacy of this approach by identifying the behaviour of different passenger segments while in an international airport.Using a framework of strategic market segmentation, it identifies how travellers allocate their time having entered 'airside' and details any purchases made. Using observational research and a face to face quantitative survey, 301 passengers were tracked and interviewed.Through a broad based, a priori form of segmentation, significant differences in shopping behaviour are identified. Such findings assist with the development of the airport's commercial strategy and allow a number of observations to be made about the value of market segmentation from both a theoretical and managerial perspective.