This concept would be foreign to most Europeans, but increasingly here in the states it's expected we tip on everything, including at over the counter places like Starbucks.
This is insanity. I'm not gonna tip on a burned cup of coffee that already costs $2.50 and takes you 3 seconds to pour. And for context I always tip 20-25% at a restaurant where I'm waited on, I tip the guys that clean my clubs $5 each round, the shoe guy $5, and the dealer at least $1 for each pot I win in the poker room (and more if it's a bigger pot.) So I'm not necessarily anti-tipping. I guess I'm just anti-tipping for services that shouldn't require it - like pouring me a cup of coffee.
It's becoming ridiculous.