Im not really an attractive girl... so are these acts just out of platonic adoration or casual niceness?

First and foremost I am not attractive... or at least i am pretty sure I'm not that attractive compared to many other girls... But there's a lot of guys that I talk to when I meet them while they are working (i.e. selling food or lemonade or at a drive-thru) that often smile when they talk to me as if they are happy... and the conversation flows... and then they give me free food or drinks and hook it up!! i dont even know these people and thats really damn sweet!! I'm not even cute so why is this? I've gotta be doing something right to be getting some free food... Help me pinpoint it guys... So that I can find a way to compensate for my lack of physical cuteness when I try to swoon some guy in the future haha