Rather than a retail outlet, “an airline amenities program is a marketing opportunity, first and foremost,” says Elizabeth Sullivan, director of corporate sales at L’Occitane. “It’s about exposing your product to as many people as you can.”

When a carrier decides it wants a new supplier for its giveaways, it starts a tender process in which it accepts bids from various cosmetics companies. Because firms want their products seen by as many people as possible—especially people with lots of disposable income—they can be counted on to give the airlines a major break in pricing.

Once signed on as Delta’s supplier, L’Occitane provided the carrier with millions of tiny versions of its bestselling products, including hand and face cream, at well below retail cost. According to Sullivan, L’Occitane marks up products as much as 600 percent for retail sale, whereas the markup is closer to a razor-thin 12 percent for an airline deal. This level of discounting is typical of airline amenity contracts, especially at a time when major carriers are strapped for cash.

“L’Occitane was looking to drive traffic to retail boutiques,” Sullivan says. “Going to a U.S. airline gets that accomplished.”

L’Occitane’s deal with Delta ended in 2005, and surprisingly, Sullivan says, the firm made no effort to track its effect on U.S. retail sales. But providing products to third parties at low cost remains an important part of the company’s business plan, and partnerships remain in place with airlines such as Qantas, Lan Chile, and TAM Linhas Aéreas, as well as with the Four Seasons chain of hotels and resorts.

Even for a well-established brand, an airline-distribution deal can be a big opportunity to showcase a new offering. This October, Bulgari, the jewelry and cosmetics company, will partner exclusively with Emirates to offer products from its new line, Red Tea, which will expand Bulgari’s already considerable presence in the amenity kits of global carriers. For Emirates, the partnership is a coup as well. “It’s a great move forward,” says Daly, who won’t disclose the financial details of the deal, which was cemented about a year ago, but says that, generally speaking, first- and business-class amenity programs cost “multiple millions of dollars” to maintain.

Because airlines care deeply about the goodies they give out—which give them a chance to polish their prestigious first- and business-class brands—the investment is worth it.

“Handing over the amenity kit to the passenger—it’s a ceremony, same as presenting a cup of tea,” says James Boyd, a spokesman for Singapore Airlines. “It helps our passengers feel more looked after.”

Boyd says that while Singapore Airlines makes a substantial investment in its amenity kits, “we always get a great deal.”

Last year, Singapore switched suppliers from Bulgari to Ferragamo. First-class bags are now fire-engine red, with the Ferragamo logo embossed on the front. Passengers receive body lotion and hand cream, lip balm and a spritzer of perfume.

Even more luxe are the Elemis bags, with pint-size versions of one of the toniest face creams on the market. “We are offering customers the premium product,” says Frank. Walk off the plane with enough amenity kits, and you might even make back the $4,000 to $10,000 that a roundtrip New York-to-London Club World seat will cost you.