Here's a fact that probably won't surprise many people.
Flights to Las Vegas make the most money selling beverages of all domestic routes.
"Alcohol sales on the way to Vegas are higher for sure than on the way back from Vegas," said Brett Proud, CEO of GuestLogix, a Canadian firm that tracks what millions of people buy when flying.
In the first half of this year, six airlines in North America tracked by GuestLogix made 58 percent of their onboard revenue by selling beverages, 38 percent came from food sales and 4 percent from the sale of passenger comfort items like headphones and movies.
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Frequent flier Evan Sears isn't surprised the average flight to Vegas made $109.70 off of beverage sales. "I was on a flight to Vegas just last week, there were a lot of people getting it going early."
Longer flights, more money
CNBC asked GuestLogix to analyze more than 2 million in-flight transactions from the first half of this year. One trend stands out: The longer the flight, the more we spend.
"On flights with duration of 2½ hours, we're seeing more and more folks open up a tab onboard," said Proud.
That's one advantage of more airlines going cashless and requiring customers to pay for drinks, food and movies through a credit card.
So what routes in the U.S. bring in the most money for drinks?
- Tops is Detroit to Las Vegas, with average drink sales of $179.12;
- Next is Seattle to Orlando, collecting $154.08;
- Third is Minneapolis to Fort Myers, Fla., with average beverage revenues of $145.07.
Each route features flights longer than 2½ hours.