Alexa, how can I fly to Mumbai?

When Karan Mehrotra booked a flight from Delhi to Guwahati, he did not go to a travel agent or an airline website.

Instead, he turned to Amazon, the world’s biggest online retailer which now sells tickets to Indian customers and offers them an easy payment process and cash-back offers.

“It was just a lot simpler,” Mehrotra said of booking a flight through Amazon. “They are integrating most of my lifestyle needs under a single platform.”

Airlines are concerned that Amazon’s quiet launch of domestic plane ticket sales in India last month is only the start of a global trend and the beginning of a battle for control of valuable traveller data.