Before I became a manager at my store I started out as a delivery driver and tbh I never did expect the people I was delivering to to tip me, sure I was happy when someone did but if they didn't I still did my same service.

On the flip side what did really piss me off is when you get customers on the phone who think they have a right to walk all over you because your doing a food related service, I have been in quite a few different retail jobs and never before have I met a more vicious bunch of people if their pizza was 5 minutes late, I would however always remain calm and civil to them.