Just the tip.

[Goldenboko]

I was told tip used to stand for, to insure promptness. That's my definition if someone should get a good tip usually.

Now by that definition the premise of tipping at the end for quality service is wrong, you should be tipping in advance of service received.

The only time I might throw a tip in advance in is if I'm chatting to a barmaid and say "oh throw one in for yourself" or something when ordering shots.

I always took it as "to insure promptness... again." So if the person was prompt, I will tip well, so they are prompt next time I am there.