sekundarburnes - as a mover i used to get crazy good tips. don't know about furniture delivery. i do food delivery now and then and i can tell you the reason tipping is standard practice for delivery boys is because their base pay is lower in anticipation of the tips they will make. same for waiters and any other job where tipping is customary, except for moving. i used to make 25 an hour doing that PLUS tips, which were usually 20-30 per customer. it was just a ridiculously sweet deal. i couldn't figure out why the pay was so good for work that anyone could do.
I think people in my area are just assholes