What effect does interface change have on user behavior?

I drive past a gas station every day that displays its gas prices using cards. I don't know whether the attendant has to manually change the cards every time they change the price or whether they have some kind of automated system that rolls the cards around, but I assume the owner must have considered whether or not to update to a digital display.

If the gas station updates their display to something electronic like a digital display, I assume many users would notice the change.

I wonder what the effect would be of such a change. Would users be more likely to notice and read the prices on the electronic display?

If users would be more likely to read the prices (purely as a result of the change, regardless of whether it is more visible, which it may be), I then wonder what the result of the increased attention would be. Would those users be more or less likely to purchase gas at that gas station?

Would upgrading to a digital display be likely to increase or decrease sales at the gas station? Is there an answer to this question based on research?