That used to happen to me as well--back in the old single days. I was a bartender and so most of the customers would know my name but I would only know them as rum-n-coke, Coors Light, etc.
After the frustration of being asked out and not ever getting a name, I started telling them-with a sweet smile, of course--that I have a personal rule against going out with people before I know who they are. Introductions rapidly happened.
If I was in a bad mood, I would say in a nice and polite voice that I would consider going out with them, thanks for asking, Coors Light. They figured that one out after a couple of seconds.
For someone I might want to go out with, I held out my hand for a handshake and said, Hi, I am Steff, and you are....
Don't take it personally, I find myself talking to people my hubby does not know and just because I know who they are, he must, too.