What is the other one? Happy toilet is good toilet? :) (Or that'd work only in plural?)
I think I better translation would be "cheerful service is good service." Actually I tried that and Duo dinged it. So I'm going to flag it.
No, I think it is a phrase describing the idea that someone who is happy provides a better service. "A happy servant is a good servant" in other words.
Sherut-service <> sherutim-toilet. BTW can someone enlighten me if "services" is also שרותים? And what about a "bus service "? Is that שרות or rather קו?
Kav means line and that is how buses seem to always be referred to in Israel, except the minivan buses/shared taxis which is monit sherut.