Any reason why?

OP already posted it was a mistake.

As to why the OP or myself might make that mistake - 3 x3 seating maybe vs 2 x3 seating. Unless you tend to "count" seats, one could make a poor assumption.

Yes, yes, Yes, - I now realize the other is longer and therefore more seats.

When are you flying this route? IME the route is significantly less busy than DCA-ATL and I have had good-great UG percentages as a FO, GM and now fantastic UG percentages as a PM. Usually fly on Sundays and Fridays.

As for the $500, I would of jumped on the chance immediately and asked to be put on the DCA flight and either taken the Metro or Cab to your destination.

I believe Delta is making these decisions with a little more information than a small set of anecdotal evidence.

If I may, how does one purchase a ticket without a seat assigned? The only time I've run into that, on Delta at least, was when my wife and kiddos (4 and 2) were traveling with me over Thanksgiving. My employer would not let me purchase the tickets and expense back my portion so we had to fly on two separate itineraries. At time of purchase the only seats left were exits and C+ at $55/seat. We were already at our budgeted max (had to purchase C+ on one of the outbound legs) so they had no assignment when we got to that gate. They were never on the "Waiting for Seat Assignment List" and the agent did a good job getting them together but I imagine this case borders on the extreme.

There can be a number of seats left for gate control. Also, every seat could be filled but open seats in first that will eventually go to a Medallion but they aren't ready to give it up. Finally, they have actually sold more seats than their are physical seats.

Ah, that makes perfect sense. Thank you. /s ;)

Seriously though, having browsed the forums here for quite a while I've learned quite a bit from the regulars (yourself included, many thanks). That, combined with flying Delta almost exclusively and seeing the change in PAX complement just in the past year, prompted my question. Even "anecdotal" observations have to be indicative of overall trends.

This, this, and I wish everyone understood: this.

Load factor and yield are two completely different things. Most flights are full these days (on all airlines). Most of those "full" flights don't make money...marinate on that.

I guess this would be the point of the whole "First Class Monetization" thing, Status being dependent on fare value and not actual miles flown? Looks like I've got a bit of homework to do.

Again, thanks all. This thread has served its purpose before veering wildly off-subject.

Also keep in mind things like fleet utilization and the ideal range of the aircraft, in addition to the capacity. A 757 or A319/320 has a greater range and is much better used on longer routes while the 500 mile hop to IAD gets the planes with the shorter range.

Think of the MDs as an up-gauge from CR7/CR9s and it makes a lot more sense. ;)

The bigger planes in the DL fleet for a domestic flight are the 160 seat MD90 and 737-800 and refurbed A320, the 180 seat 737-900, the up to 199 seat 757-200, and the 234 seat 757-300.

I travel out of DCA about 30 times a year. One issue with the 757 is space. DL only has a few gates that can handle this size plane. At busy times it's difficult for planes to get in and out between B/C because DL shares the alley with AA and B6. The other issue is space inside of the terminal.

I've had mechanical cancellations at DCA and in my experience DL doesn't really want to send you to IAD or BWI. I also can't remember the last time I saw an empty seat out of DCA.

I do use BWI a couple of times a year, but have found the airfares really haven't been cheaper than DCA this year.

In terms of AC, I like the 2 seat side on the MD and there are more F seats than the A319.

DTW has it worse off than ATL at Dulles
 

At least ATL has all of the various mainline flights that have been mentioned. Us DTW fliers have it worse. Less frequency on regionals. Admittedly, there are now larger CRs (7s/9s), but there is still a crappy CRJ on the 5-ish PM flight, IDA-DTW, that seems to be when everyone is flying home after work.

In addition, Dulles and BWI seem to be getting worse for DTW and MSP fliers with how regional flights are now sneaking in to DCA and BWI to and from DTW and MSP, on top of the regional flights to and from IAD.

Based on this situation that you observed, there's no actual data to make any judgement about how this one situation worked out for DL.

First off, you don't know whether all of those four names waiting on the screen were actual confirmed passengers without seats assigned, non-confirmed passengers standing by for a different flight (for Same Day standby or another reason), or most likely, non-revs. The screen makes no distinction between these very different reasons why someone would be waiting for a seat assignment, and none of these reasons except the first would be of any concern to Delta in deciding which type of equipment to use. Only four names awaiting seat assignment on the screen is a low number if you've ever seen that screen when it stretches to multiple pages of names, mostly all non-revs.

Also, "oversold" doesn't necessarily mean that anyone actually gets bumped. Gate agents proactively solicit volunteers when there is a risk of needing to bump someone. However, in many cases, by the 15 minute mark, it turns out that the volunteers aren't needed due to other no-shows, and are then asked to board - when this happens, Delta succeeded in maximizing the seats sold without going over. For better or for worse, we've seen many comments and complaints on this forum about the handling of the VDB process, and it's clear that volunteering and then being asked to board at the last minute is not an uncommon occurrence.

Unless you have access to Travelnet or Deltamatic to see who the standbys are and what happened with the volunteer situation, there's not really any evidence here that Delta lost out on anything with this flight.

In addition to your situation of not wanting to pay the upcharge for the remaining available seats at booking, other situations can include booking through third party sites, interlining, re-routes/IRROPs where someone did not specifically go in and select a seat when the booking was made. Usually these names do end up on the awaiting seat assignment list, shown together with but ahead of standby passengers, who of course also don't have a seat and are assigned at the gate in a similar manner.