We tip at the end of a meal and as we normally only eat in Epicurian once on a two week cruise, it don't work for the next meal, which may be 6 months later. We took our free bottle of fizz to the MDR. The kind Lady got some glasses for us and poured it. We gave her a good tip and we got very good service in the MDR from then on in. It does seem to influence them, but I agree ,it shouldn't.