Originally Posted by
channa
That, too, is inaccurate, as they're not upfaring you to discounted F fares, rather they're usually upfaring to higher economy fares.
They're aggressively marketing fee-waived upfares at checkin to people who bought economy fares to upfare to higher economy fares that they could instant-upgrade immediately.
Okay so they're upfaring you to what on UA is a Y/B upgrade fare, or a Q-Up / H-Up fare. For all intents and purposes, that's an F fare...it costs way more than a typical discounted Y, price is comparable to discounted F, and you get the EQM bonus and everything.