> I am a skeptic that one more Coke Cola ad aired at the Super Bowl meaningfully changes sales

It actually might. Coca Cola had $48b revenue last year, or in other words, 4800 millions. Spending 7 of those millions to put your product in front of 100 million people seems like a reasonable bet. If even a couple percent of those people are (sub)consciously influenced to pick up a 12-pack the next time they stop by a store when they might otherwise not have, it would likely be a profitable endeavour given the profit margins on their sugar water.

I think there's also a longer-term status play at stake. If only one of Coca Cola or Pepsi engaged in flashy advertising to this degree, it might give them a slight edge in status perception. In the long term, even an 0.1% shift in consumer preferences between Coca Cola or Pepsi would shift significantly more than 7 million in value. So if one of them engages in this, the other is obliged to follow, in a classic prisoner's dilemma. At any rate, given that 4800 millions in annual revenue translates to 13 million in sales per day, the number paid for that advertisement is a rounding error and doesn't have to move the needle very much at all to be successful.

The irony is that this especially true for Coca Cola. They are basically an advertising company at heart. They sell flavored sugar water. For all the hype about "are you a coke person or a Pepsi person", in blind tests most people can't tell the difference between coke and generic cola. The billions they spend in marketing annually helps ensure they can sell their flavored sugar water for a lot more than Aldi sells their store brand flavored sugar water.