But UA's program was not the first! In the late-1980s I was invited to join Eastern Airlines' "Executive Traveler" program. It was invitation-only, unpublished. Our membership number was our home phone number, embossed on a tan and black card. It was spend-based as well. The primary benefit was free space-available upgrades on any fare, on any flight -- granted upon check-in at the airport within two hours of the flight. The code word we used when asking was "Is an ET upgrade possible?" The ET program ended with EA in 1991, of course. It did not carry over to OnePass.

I've been a UA GS about 15 year (LT since 2019 and earned prior). ET was a lot more exclusive -- word was there were only a few hundred invitees in any year. EA would bend over backwards to fix issues, with no "this is a one-time exception."