This so true. Comments are post and we need to use it constructively which will yeald us SBD and SP when people upvote it.
However, some people dont realize this, they just mount on people's post without even spending a little time to catch the author's message, they immediately comment something like this "great post!" or "nice article" and leave.
These kind of comments will hardly get upvote from people.
I must comment you for this. It's quite informative and would help people understand the secret behind commenting.
One more thing. A well and constructive comment, attracts people's attention to you.
How i wish the participants on the challenge will understand it.
I hope they do.