I wonder whether Edward would turn into Buffy goo or Twilight sparkles.
Tipping is very important to our society. Without it, we wouldn't be able to pay people inhumanly low wages—one of the founding principles of America. So, to keep everything running along correctly, we all give a certain amount of our inhumanly low wages to the people with really inhumane wages so that we can still get someone to make the overpriced coffee that keeps our eyelids from collapsing at our own jobs. Of course, if you're wealthy, these tips don't really mean much, which is why they tend to make servers work so much harder for it.
Just shut up and give them your money, Fry.
Not sure how this encourages tips, but delightful nonetheless.
Which, at this point, would be a big improvement for both characters.