Subway Recognition

I went to Subway for another 12" manwich today. All four people working there said "Hello" to me like they knew me. This worried me a bit. I've clearly been going too much when all of them say hi to me. Or maybe I have a distinctive face. Then after I paid, the money man gave me not one, but two thick, decent books of vouchers. Quite good ones too - the sort that give you free drinks when you buy a sandwich or things like that. I've never been given those before. He must have really recognised me!