Hello! Hello?

When customers walk into Joie de Vivre, we generally like to say "hello." Just our way of saying "welcome to the store, we see you and realize you're here." I always feel that if there is some mutual acknowledgement, then the customer is more likely to feel free to ask a question, or for help if they want some, than if we said nothing when they enter. Plus, they're entering our little world - it seems not only polite, but friendly, to say hello. Yesterday a man walked in with his daughter - he was probably about fifty, she looked about ten. As they walked by the desk I said "hello" and he instantly snapped at me "We're only looking!" "That's perfectly fine," I replied - but I was taken aback - I intended my hello to convey nothing more than "hi, cold day isn't it" and he seemed to take it as "hello, I am now going to try to hard sell you lots of things you don't want." He was probably just having a bad day but it made me think of the big stores where people are paid to greet you and ask if they can help you the second you walk in the door. And that is kind of fake and annoying, and I feel sad if someone can't tell the difference between that and what I hope is a genuinely friendly hello !