You should never hesitate to greet customers when they walk in your business. It does not matter what they look like, what they are wearing or what their body language is. It only takes a second or two of hesitating to lose a sale to someone else who is quicker than you in their approach to the customer. I can testify that many of my co-workers have lost thousands of dollars to me by momentarily hesitating for a second or two by the appearance of a customer. Their mind quickly tells them that the customer does not have any money to spend or something similar to that in thought and bingo they lose.