wow I tip 10-15% if it is good. Hell think of it this way. average tab for 2-3 (food, drinks(age 21+)) is around $50. Therefore $5 tip. Doesnt seem like much but...at the same time the server is probably waiting 4-5 tables. So if each table was there for average of an hour and each table had the same rate/tip thats almost $30 an hour. If that person averages that for 5-8 hours a night 4-5 days a week, there making plenty money.

But maybe its just me and I have had jobs where it is tip dependent and I think of it as a average per how many at the time.