People don't typically hang out at gas stations. You go there to get gas or buy whatever you need inside, and then leave. People buy their cigarettes and then take them somewhere else to smoke them (usually their homes). 

We do not see any cigarette can be bought in gas station in Taiwan.  It must be dangerous smoking in gas station anyway. You might choose buy in gas station . however, you will not be allowed to smoke in gas station . 

Fortunately in my country, I have not seen cigarrete sales in gas stations. But the comment that you do, it seems to me something unusual.