Why airlines want your miles to expire.

Why Airlines Want Your Miles to Expire (Except They Don't Anymore — And That's Worse) In 2025, Delta made $8.2 billion from American Express — without a single passenger flying anywhere. That's not a typo. It's the wholesale price of a currency you didn't know existed: airline miles. This video follows the money through seven parts: ✈️ Loyalty programs are now worth more than the airlines that run them — SkyMiles alone has been valued at $31.7B, roughly 4x American Airlines' entire market cap. ✈️ You don't earn miles by flying — airlines manufacture them and sell them wholesale to banks, who hand them to you to encourage spending. ✈️ That "free" flight is quietly funded by interchange fees baked into everyone's grocery bill, including people who will never fly (NBER, Harvard, and Boston Fed research cited — and the contested counterarguments too). ✈️ Most major US airlines actually stopped expiring miles years ago. Here's the real reason, and why it's not generosity. ✈️ Since Delta killed its award chart in 2015, airlines set both sides of the transaction — printing the currency AND pricing what it buys, with zero obligation to announce changes. ✈️ Your mile balance is functionally an interest-free loan to the airline — Delta is carrying ~$8.8B in deferred loyalty revenue on its books. ✈️ And when the issuer collapses — as Spirit Airlines did in May 2026 — your balance can vanish with no insurance, no regulator, and no recourse. Miles aren't savings. They're a coupon that doesn't print its expiry date on the front. 📚 Sources referenced: Delta/United/American SEC filings and investor disclosures, NBER interchange fee study, Harvard research on premium cardholder benefits, Boston Fed research on cross-subsidization, Spirit Airlines bankruptcy filings (2026). ⚠️ Some figures (interchange pass-through effects) reflect contested academic research — see video for the counterargument. #AirlineMiles #Aviation #Finance #Economics #CreditCards #FrequentFlyer