Ok, maybe I mis read you there.
How about this, let's say you are a 15% tipper wherever you go. If it's good service it's 15% if it's bad it's 10%.
Having said that, what if you go to a joint tonight, you order a meal, and have 4 beers throughout the night while watching a 3 1/2 hour game. Service was good, not great, but the place was packed and the waitress was slammed. What do you tip, 15 or more?
Now mind you, normally you are in and out of this joint in 45 minutes to an hour and you buy a meal and a drink. So now you've taken up almost four times as much time at this waitresses table and only purchased three drinks more then you'd normally purchase.