I lighten others lives with a kind-hearted smile.

Four hundred people walk past the security desk between eight and nine in the morning, and roughly six of them look up.

A smile is thin material. It fixes nothing, pays nobody, changes no rota. What it carries is one small piece of information: you were seen, by someone, at ten past nine.

For a person who spends a shift being scenery, that information is not nothing. It's also free, which makes people suspicious of its value. Cheap and worthless aren't the same category.