It will always be a good thing if you are going to give some tip to a person that gave you a good service.
Treat it like a gift to him.
You are right it is not that bad to give a tip as a gift for those people who are giving good service to us. And for sure they are going to appreciate any amount and that's how tipping works. It's not all about the payment that we need to give to them but it's just a simple token of appreciation that we are loving what they did to us.
You are right about tipping is for the token of appreciation. But sometimes, tipping is also for giving other people who are badly in need. I'm speaking on gambling tipping. Because i think you are pertaining on tipping for the great service just for free. I always tipped other user everytime i won huge btc with no string attachment.