MIAMI (CBSMiami) – Southwest Airlines has become the latest air carrier to give passengers the choice of paying a fee to get extra services.

According to the Los Angeles Times, Southwest has introduced an early-boarding fee option. The $40 charge would guarantee a passenger they will be one of the first 15 passengers on the flight.

Southwest had previously offered a $10 Early Bird Check-In service to bump passengers up the list of boarding. The new early-boarding fee option will be available online and at the gate up to 45 minutes before boarding, according to the Times.

Airline fees have become a gold mine for the once struggling industry. In 2012, the world’s largest air carriers collected $36.1 billion in revenue from fees for everything from roomier seats to wireless Internet service.