Show ads on the screen -> screen is vandalised -> nobody can buy gas anymore -> people go to the gas station without ads (and thereby functioning screens) -> lose money to the competition-> recognise that you lose money by blaring ads -> stop blaring ads -> … -> profit
The screen used for blaring ads is the same screen that you have to read to be able to use the pump.
Show ads on the screen -> screen is vandalised -> nobody can buy gas anymore -> people go to the gas station without ads (and thereby functioning screens) -> lose money to the competition-> recognise that you lose money by blaring ads -> stop blaring ads -> … -> profit