I smile at pretty much anybody. However I noticed that not everyone wants to smile. Did you ever get those few that you smile at and they look at you like you're filth? I have. I than stuck my tongue out at them. I don't know why I do this. It's made a few angry and they start yelling. I laugh at how people are. Any way I don't think it's a bad thing to smile at everyone. It just might put someone in a good mood. You never know.