The exploration of existing commercial opportunities has been increasing the share of commercial (non-aeronautical) revenues in the total revenues of airports worldwide. These revenues, also called commercial, non-aeronautical, or non-tariff revenues, come from rentals, duty-free shops, food and beverage sales, parking, advertising, etc. In other words, everything that is not the main business of the airport. Consequently, the dependence on commercial revenues has also become increasingly important, and airport managers are interested in understanding how to improve their financial results with this new revenue source, as it not only improves financial outcomes but also optimizes passengers' time and money consumption options at airports. Therefore, this chapter seeks to discuss the main determinants of commercial revenues at national airports, analyzing the possible impacts of the behavior of passengers from low-cost carriers (LCC) on these revenues, combined with other determining factors.