Again, 99.999% of the viewers aren't really in the position to finance a $120 million fighter jet. However, the ~0.001% that are in that position will probably be watching, and feel FOMO for not having the iPhone of strike fighters.
Even if it only moves the needle on 2-3 sales every decade, the ROI is probably great.
I'm just saying, that random saudi prince or whatever with $120 million and the green light to buy military hardware is probably well aware of the f35 already. Plus only plane nerds in the know are going to know what the hell just flew over. For everyone else its a military jet shaped jet same as the rest.