The company analyzed the inflight sales of five carriers between November 2013 and February 2014, breaking sales down into categories including comfort items (pillows, headsets, in-flight entertainment, etc.), food (both fresh and packaged) and beverages. Sales of liquor, beer and wine accounted for 99 percent of all beverage dollars spent by passengers.

Seems that alcohol is quite popular in US skies, bringing in more revenue than comfort sales (pillows, headsets, etc.), though:

Fees for checked bags, says Sorensen, dwarf what airlines get from selling alcohol. The difference, though, is that while baggage fees have plateaued, beverage sales and other onboard sales are continuing to grow.

The kicker?

The airlines that get the most revenue from their beverage sales … are those that "think like a bartender."

The one that does that best?

Think like a bartender (image courtesy of Virgin America)

Not only does Virgin America let you order cocktails from your seatback, it lets you run an open tab.