Case in point:
Andrew Tanenbaum: I said that his work was amazing and thanked him. He shrugged me off. I think he felt busy or didn’t care. I was happy that he listened.
Jane McGonigal: retweeted my question while I had 0 followers and followed about 10 people.
A semi-famous Dutch rapper: he was appreciative.
I have many examples with non-famous people too. The rule applies to both. I originally learned it as a dating concept (a decade ago) but quickly decided to compliment anyone that I genuinely wanted to give a compliment.
The reason it can still be quite amazing is simply because strangers don’t dare to compliment other people that much. I have only seen it once from another person.
You can test this theory by giving a compliment to someone you think never receives it but deserves one (my go to: cleaners, especially if it’s really clean) and to someone who does receive them more often.
My experience: both can still be quite awesome but the cleaners I complimented really went out of their way to be appreciative (not always, just sometimes). One even invited me to his home and I discovered he also was a music producer on the side. We made some music together as I am a hobbyist myself.
I never looked at cleaners the same way again.