I've had many such experiences. I've had one author enthusiastically accept my suggestion for naming a concept he had misnamed; my proposed name will has entered the research literature and may become standard jargon in his field. It's always satisfying when I can identify problems with an author's research, propose a solution, and see that solution adopted in their future writing; that happens fairly often. I always try to teach authors how to do things better, and the ones who learn from my teaching and become better writers are an ongoing source of pleasure. Word of mouth referrals to friends and colleagues are the highest possible compliment.