Is it appropriate to comment on a good Code Review answer to one of my posts with a "Thank you"?
There are multiple things you can do, most of which unfortunately require reputation.
If you think one answer is better than the rest, then you can accept the answer by selecting the hollowed out tick under the voting buttons. This gives the answer 15 reputation.
At 15 reputation you possess the ability to up-vote questions and answers. This gives an answer 10 reputation. If you think the answer is good make sure you've up-voted!
At 75 reputation you can start a bounty giving 50-500 of your own reputation to an answer.
If you wish to give something to an answerer it's encouraged to give the up-vote and the accept. (25 reputation)
As an answerer, I always enjoy it when a user gives a warm thank you. If it's one comment I don't think it's 'too chatty', but expect no response from the answerer, as then you'd both be 'too chatty'.
The Help Center page What should I do when someone answers my question? states the following under the heading What should I not do?:
Please refrain from posting a comment that merely says "thank you." Voting and accepting are the preferred ways of saying "thank you" on this site, as they confer reputation points. Comments are meant for requesting clarification, leaving constructive criticism, or adding relevant but minor additional information—not for socializing.
Also, from the Help Center page for the Comment Privilege:
or for brevity/posterity:
When shouldn't I comment?
Comments are not recommended for any of the following:
- Compliments which do not add new information ("+1, great answer!"); instead, up-vote it and pay it forward;
I would argue that it feels nice to get a comment like "thank you so much, I had no idea X was Y and you made me realize Z". In fact, this feels much nicer than just a +1 which could come from anyone (or a bot for all I know).
But at the same time, everyone should realize that comments are always temporary. That is, if I add a "thank you" comment, I make sure to remove it after a day or two once the person it was given to has seen it. Also, if I see such comments anywhere after several days, I flag them for being too chatty.