You know that. I know that. The airlines know that. Probably _most_ FTers know that (although we seem to get a question about "direct" flights at least once a month on the NW board).

But 99.9% of the population has no clue that "direct" doesn't mean "nonstop." Do a search for "direct flight" on google news, and every single article involves a nonstop. Sure "nonstops" are technically "direct," too (just like squares are technically rectangles). But "direct" flights should not involve changing planes, let alone all the shenanigans with seat assignments, upgrades, reduced mileage/segments, etc. I've even seen folks on a "direct" flight misconnect to their onward leg. There's nothing quite like watching a hapless GA try to explain to an irate mother why he didn't hold the plane for her family of 5 who just sprinted from MSP's F12 to C27 as part of their "direct" (as advertised) flight.

Other than saving a few pennies in taxes, "direct" flights with stops do not benefit pax. There was a time when you could at least stay on the plane during the stopover, such as my first solo flight, when at age 8 I flew TW's "direct" MLI-IAD flight via STL. But they probably wouldn't let you stay on the plane these days even if you had the good fortune to be on the rare direct flight where they actually used the same equipment for both legs. And some "direct" flights don't even leave that possibilty open, since they use different types for different legs (e.g., CO's EWR-OGG "direct," which swaps a 757 for a 767 in IAH).

The terminology is flat-out misleading and should be abolished. A flight these days is either nonstop or connecting.