From an economic point of view, it’s not a mystery why airlines are engaging in this somewhat heavy-handed sales tactic. Branded credit cards are big business, and in-flight pitches are seen as a way to sign on more casual fliers—ones that might not be privy to the latest card releases. And from a marketing standpoint, one can’t argue that a flight full of belted-in passengers is the very definition of a captive audience. As Skift noted, “everyone, from the bank to the airline to the flight attendant, gets a cut.”

But that’s not to say there aren’t pitfalls, namely to do with passenger experience. By trying to encourage loyalty in its less frequent passengers, airlines run the risk of irking their most loyal flyers—those with elite status or airline-specific credit cards and would rather not hear a sales pitch on multiple flights per week. In addition, concerns have been raised by some that the pitches aren’t always accurate, though American Airlines clarified to The Points Guy that any deviation from the script would be taken seriously. Either way, it’s not hard to see that an airplane seat perhaps isn’t the best place to review the T&Cs of a credit card application.

In a statement to Skift, a United spokesman confirmed the new training program and said “our inflight crew are effective ambassadors, who can best communicate to our customers in the moment the benefits of the United Explorer card.”

Meanwhile American Airlines told Quartz that while their credit card program is an “important and profitable” part of their business model, participation is voluntary for flight attendants. “We have found that inflight is a great time to talk with our customers about airline credit cards,” a spokesman said. “They’re often thinking about their next trip while traveling and American Airline’s co-branded credit cards are a great way to get them closer to that next trip.”

This post has been updated with comment from American Airlines. Quartz has reached out to United and will update this post if they respond. 

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