I just flew for the first time in 5 years. It was a weekend trip to visit a friend.
When I bought my tickets online the site offered me a link to pick my seats, but every seat was marked as unavailable both coming and going. Even though I was buying almost a month in advance, I assumed this meant the flight was overbooked.
I didn’t worry too much about it as I am pathologically early and figured checking in early would mean I got on the plane.
Both flights I ended up seated in first class! In the future will skipping picking my seats online increase my chances of a free upgrade? Or is that dumb?
My suspicion is that if there are available sets when you book, you will be randomly assigned to one in coach. You are given a choice in case you have specific preferences. Your plan would only work if coach was booked solid before you reserved your seats.
No “strategy” to get upgraded works consistently. I mean, other than the published ones - being a top tier frequent flyer, using upgrade instruments, paying actual money, etc.
You were very lucky - good for you! Don’t be disappointed though if it never happens again.
Years ago before I retired and was still flying a lot (150,000 miles a year or more) I was occasionally moved to first class so another coach class flyer could be seated in coach.
On one airline I was told that the policy was to offer someone dressed in a suit and tie a chance to move up if the other guy was not so dressed. Another airline had my frequent flyer status on the manifest and used that to qualify me.
I don’t think there is any way to consistently get bumped to 1st Class besides being a very dedicated frequent flyer but I have had it happen a dozen or so times over the years. One of the best ways is to volunteer to give up your seat if the flight is overbooked. There is a chance that you will really get bumped so you can’t do it if you have to be somewhere at a certain time but you get a free ticket or money voucher if you do. What usually happens is they seat everyone else and then put you in 1st or Business Class just for volunteering. Appearance matters a lot in getting bumped to 1st class and the gate agents have discretion. Dress like you belong in 1st class every time you to the airport or it probably isn’t going to happen.
When you go to the “pick seats” page and find nothing available to preselect it may not really mean there is absolutely an overbooking, it can also mean that airline fixes a threshold of some X minimum number of seats they want to hold back on assigning until actual check-in, in case they need to move people around.
OTOH if indeed coach is overbooked by one or two and everyone showed up, and by some freak coincidence First/Business is mostly empty after the no-more-check-ins marker, they may give a break to someone who has made a good impression when dealing with them, as per Shagnasty’s observation.
It works the other way too. Without seats assigned, if everyone shows up for the flight, and the flight is full and someone needs to be bumped - guess who? Not the folks with seats (unless they volunteer).