Good question. I asked myself the same thing. Since airlines are mandated to produce a safety video regardless, the ROI they really have to assess is against that incremental spend on making the video cinematic/entertaining. And if you factor in that potential to go viral and get good PR from it, as well as the fact that they can produce a video once and reuse possibly for X years, the incremental investment doesn’t sound that unappealing. Also: traditional methods of advertising (say renting a billboard) are just as expensive, if not more.

It’s a captive audience which you can directly target for retention. In 3 months when they go to buy another plane ticket they’ll remember the catchy funny video and associate that airline with positive feelings when making a choice.