I always wondered this too.
Found a website saying Youtube adviews are $100-300 per 10k (ad views, not video views). That’s 1-3¢ per view. If we assume an ad is 10seconds, then your time is worth 0.1-0.3¢ per second, or $3.60-10.80 per hour.
An A380 looks to be 380-615 seats. I’d imagine they’re more often optimising for space, so let’s say 550.
Long haul flight, 10% of people at any time using inflight stuff, 8 hours, 4 ads per hour = 5500.18*4 ads watched. 1760 ads. There will be a massive premium for planes, but surely only one order of magnitude more (e.g. 10x). That’s equivalent to give or take 20k YouTube adviews which would be $200-600 per flight.
There are a lot of planes in the sky every single day though…
ROI from adverts is always a shitshow though. If you come off a plane and see <brand name product> and buy it, is it because you just saw an advert for it, or were you always going to buy it. There is of course stats that may show number of impressions vs. total purchases trend, but its still just massive correlation that I imagine there is a bunch of people pulling spreadsheets together to justify their marketing spend. Anecdotally, I’ve heard of data teams working with marketing teams and just going “whelp, whatever you need to justify your job”, etc.
Real ROI via direct sales though, that’s somewhat measurable since you have a direct cost of acquisition (sales person salary, overheads, etc) vs revenue.