In their ongoing quest to squeeze more revenue out of passengers, airlines are split on a big potential moneymaker: in-flight entertainment.

Large carriers such as Delta Air Lines have invested heavily in touch-screen entertainment systems that are built into seat backs. Southwest Airlines and others offer only onboard wireless Internet so passengers can watch movies and television shows using their own tablet computer or smartphone.

A few airlines have installed both systems.

What kind of in-flight entertainment an airline offers reflects the type of passenger carriers are targeting. Airlines with seat-back systems are going after well-heeled fliers with money to spend on onboard food and entertainment. Carriers with only Wi-Fi hope to attract thrifty travelers looking for the cheapest airfare.

The split was illustrated at a recent airline industry expo in Anaheim, Calif., where manufacturers of touch-screen entertainment systems shared the exhibition floor with makers of onboard Wi-Fi equipment.

Big money is on the line. The nation’s airlines pocketed $27.5 billion last year from onboard sales of food, liquor and entertainment and all other revenue besides fares, bag fees and reservation changes.

There are drawbacks and benefits for each entertainment system. Seat-back systems can cost $6 million and weigh as much as 600 pounds per plane, depending on the size of the aircraft. But the systems can generate big revenues by having passengers buy food and entertainment with a touch of the screen.

Passengers on Virgin America, for example, can swipe a credit card on the seat-back system at takeoff and keep a tab open for an entire flight.

Carriers offering only onboard Internet call their strategy BYOD, or Bring Your Own Device. Onboard Wi-Fi systems weigh only 70 or 80 pounds.

"With the vast majority of our guests already bringing on board their own devices, it makes sense for us to provide them with the content they want on the device they want to watch it on," said Robert Palmer, a spokes­man for WestJet of Calgary, Alberta.

Hugo Martin, Los Angeles Times