This module introduces the concept of ancillary revenues. Their prominence in the airline industry and the extent to which they have become vital to many airlines’ revenues, profitability and survival is analysed and evaluated. Many airports have also introduced ancillary revenue strategies in an attempt to increase income streams. The three main categories of ancillary revenue are analysed as is the importance of ancillaries in airlines’ marketing and advertising strategies. Finally, the module examines the impacts of technological developments on ancillaries.