Not all air travellers have the luxury of buying their tickets in advance. Most major airlines offer ticket sales at the airport, giving people who haven't bought their seat an opportunity to do so at the last possible moment.
Customers can find ticket counters throughout the airport. Once a traveller finds the airline of his choice, he approaches the ticket agent, provides the relevant information (destination, date of return flight, proper identification) and is issued with a ticket. Ticket counters accept most major credit and debit cards.
By purchasing a ticket at the airport, a traveller can take care of everything in one place. Most ticket agents are able to process a traveller's identification, issue a boarding pass and pass along any checked luggage at the same booth.
Tickets bought at the airport are often more expensive than ones purchased online, or through a travel agency. Additionally, customers who wait to buy a ticket at the airport won't have many seats to choose from, since the majority of seats have already been filled through online or travel agent purchases.