I've been active on many Stack Exchange sites and post many Questions and Answers.
I know I like it when I get feedback when I post answers, either in the form of an accepted answer or a comment from the OP (original poster) or both when I answer a question. Even if it's upvoted and the OP makes no comment, I feel a certain loss at not knowing if the answer helped them.
I also like it when other users comment on my answers and I will leave feedback on answers that are particularly helpful or occasionally, if they're completely wrong (the notion of being wrong is more for the programming sites).
As such, I feel obliged to give people feedback when they answer my questions. Often though, there's not a lot to say, except - "this is a great answer" and we're supposed to avoid those types of comments - as they're noisy.
Is there an etiquette to giving feedback on answers posted to questions?