The $1.8 billion price tag on a stake in Air Canada's loyalty program suggests high valuations for the much larger programs operated by Delta Air Lines and United Airlines.

Air Canada sold the 25% Aeroplan program stake to Blackstone and some leading Canadian institutional investors, valuing the program at more than $7 billion U.S. dollars ($10 billion Canadian dollars), according to a news release Tuesday.

The sale sheds additional light on just how big a part Delta and United's own programs likely play in their businesses.

Based on the valuation of the Aeroplan stake, the Delta SkyMiles and United MileagePlus loyalty programs could each be worth $30 billion or more, which would be a significant chunk of each airline's market values, Jefferies analyst Sheila Kahyaoglu wrote after the sale.

Delta and United -- the two largest U.S. carriers by market value -- are valued around $60 billion and $40 billion, respectively. Both companies carry sizable debt or lease obligations for aircraft.

Delta stock was down 0.2% Wednesday to $90.17, while United also edged down 0.2% to $126.

Analysts have said the major air carriers amount to loyalty programs with airlines attached. That might overstate the importance of the programs, but not by a lot.

Delta and United don't break out the profitability of their programs, but they likely are lucrative, likely accounting for a sizable chunk of their profits. Delta realized $8.2 billion in revenue in 2025 from American Express, its credit-card partner for its SkyMiles program. The American Express payment amounted to 1.4 times Delta's pretax operating income of $5.8 billion in 2025, highlighting the financial importance of the relationship.

The two airlines control 100% of their loyalty programs.

In its 2025 10-K report earlier this year, Delta said aims to get $10 billion annually from American Express in the next several years. Award travel also contributed a notable amount of last year's flight revenue.

"In 2025, 12% of revenue miles flown on Delta were from award travel, as program members redeemed miles in the loyalty program for approximately 35 million award tickets," Delta said in its 2025 10-K.

The programs are lucrative because Delta, United and other airlines sell miles to credit-card companies, which offer them as tax-free benefits to their cardholders. United's card relationship is with JPMorgan Chase.

Credit-card companies are eager for the airline relationships because cardholders tend to spend more on the co-branded cards and generate fee income to the banks from merchants when customers make purchases. Delta noted at its 2024 investor day that the co-branded Amex card has shown above-average growth relative to the credit-card universe.

These loyalty programs have evolved from their original purpose of incentivizing airline passengers to stick with a carrier by offering free tickets after a certain number of flights or hours flown to complex relationships that involve credit-card partners.

While these programs are set up to give away flights and other perks, their structures still lead to profits.

"Modern loyalty programs have created a unique system in which the carrier is able to fully control both the accrual of loyalty points while also serving as the only real place where they can be redeemed," Alexander Mitchell, o n the Simple Flying website in 2024. "As a result, carriers have begun to profit off of a currency which they alone control, one for which they are the only source of creation or redemption."