Always.



I generally average about 20%, more for good service, less for poor service, but never less than 10%.



If I am generally able to do something myself, and choose not to, allowing someone else to do it for me, I tip. I don't tip my doctor, but I will tip the delivery driver and waiter. We could call it a laziness tax.



Absolutely.



Same reasons as above. Also, I did it for a time while in college, and though I was never paid less than minimum wage, I wasn't paid enough hourly to cover all my expenses. Tips kept my car working.



Or the people who give you $15 on a $14.99 order and make it a point to say "Keep the change."



Wow. When I worked delivery, I got paid minimum wage, which was $5.15/hr. I got periodic raises, though, and when I quit after two years with the company I was getting $5.60/hr.






I was fortunate enough to not work in a dangerous area, but even with a relatively low crime rate, you're still expected to drive in sometimes dangerous conditions. When there's a blizzard outside, the pizza places get very busy.