Since most airlines began nearly a decade ago to charge for extras that previously were included in the cost of the ticket, freebies have become rare for air travelers.
But there are a few exceptions.
The latest example is Delta Air Lines, which on Oct. 1 began to let passengers on most flights use their smartphones, laptop computers and digital tablets to send messages for free, using the carrier’s onboard Wi-Fi system.
The program lets passengers contact friends and family via iMessage, Whatsapp and Facebook Messenger.
Alaska Airline launched a similar service earlier this year. Not to be outdone, American Airlines’ chief executive, Doug Parker, announced...