*most* of the point of tipping is because servers don't even made minimum wage -- they make more like $2.50 an hour THAT IS ALL. Their tips ARE their wage.
When someone does an outstanding job for me (like the guy who is my colorist and the awesome woman who is Billy & Kee's groomer) I tip 20% plus whatever I can.
People on a till MAKE minimum wage and I don't tip them any more than I'd tip the girl who rings up my order at Wal-mart
Now if I'd handed that salad to the guy behind the counter to 'modify' for me particularly that's different. But no -- I don't get conned into giving a tip when they already make an hourly wage and it is their choice to stand there (i.e., they aren't serving me specifically to ear their wage).
Now -- the kid at the curb-side take out at a bigger restaurant? YES I tip them because they go to the kitchen, package the order for you, and generally anticipate everything you need, including putting your drinks up, getting hot bread/butter, etc. They are providing the same service the server does PLUS they are bringing it out into the car (rain, cold, etc.)
David and I have some extra "rules" -- generally we are really good tippers but we also expect a lot I guess. But the server who brings back our tip minus our 'change' (your bill came to $54.15 and they gave you change of $45.00). THAT server loses a dollar (at least if everything else was ok).
Because that server ASSUMED you'd leave them a tip and take the change out of that. No -- don't presume on me, a tip is a TIP, it's not a guaranteed wage or something I owe you. It's something I do because you helped ME.
Same thing tho, that server to for the same $54.15 bill gives me back $46.00? He gets an EXTRA dollar because he was honest and didn't presume I owed him any part of my change.
The kid who snags the bill & money with a flip "You don't need change DO YOU??"-- he loses a dollar. You haven't even counted it -- you presume on me again. No way.
But the server who has been pleasant, who truly acts as if they're glad we're there and glad to help us -- they're gonna get more than 20% really often, and particularly so if they've tried to be really helpful.
However, by the same token, if a server has been abysmal and they've gotten a token 10% tip or something -- me, Ms. Quiet & Shy? I'm gonna tell the manager on the way out WHY I tipped so badly because maybe they're gonna cause that restaurant to lose business with their attitude.
An Outback we go to regularly has recently had a proprietor change and two weeks in a row BOTH David and I got knives that were ... well, let's say "three-dimensional" (caked food on the knives that were rolled UGH). Water stains don't bother me, but eating food with dirty utensils rolls MY stomach.
I snagged the new proprietor and TOLD him and he's smart enough to realize when a regular points something like that out you need to listen.
If something was really heinous and we complained and wound up getting that food comp'd **and the service was fine and the error was handled properly** -- we tip the server as if we had paid full price. Why? Because they did as much work -- and likely MORE -- because of a foul up and they shouldn't have to be negatively affected by it.
things are different today than they were 20 years ago. NOW that server doesn't *just* bring your food. They clean their area thoroughly, sweep, clean under and behind tables and often things like light fixtures and the whole coffee bar, salad bar area as well. Often a server is there 1-2 hours AFTER they get cut and their shift ends just cleaning up and setting up their area. And yet they likely only have 3-4 hours to make their entire day's work money.
But no -- as generous as I am to someone who has been pleasant and has helped serve me and make my meal enjoyable, I DO NOT buy into the guilt of a "tip jar" UNLESS it is somewhere I go often and the people really DO extra stuff for me. If I call ahead and they prepare something especially for me to go, to make my meal more pleasant -- yeah, I'll toss something in the tip jar.
But just being presented with a tip jar to guilt me into tipping when they simply rang up my order? Nope.