Okay ladies, your insurance agent shows up for an appointment!  What the heck do you do?  I know my agent by his first name only.  How many Ricks are there in Austin?
You get hurt and need a "bus" to the ER.  EMT is a hobbyist.  Or the ER doc.  Or the x-ray guy.  Or someone.
You walk into Best Buy and voice from behind says "can I help you?" and it's the guy you saw yesterday.
In my profession (medical) there is a serious and distinct cut-off.  If I see you, I don't say a thing unless you say hi first. 

  Inside or outside.  But I may see 20 people a day.  When I'm in the ER it may be more like 20 people an hour on a Saturday night!!!