We borrowed this great definition from gothamist.com:
› Good comments respond to the content in the post or to a comment left by another reader and it is helpful to write to which author a comment is addressed.
› Good comments can disagree with the content in the post but do not insult the writer of the post, other readers posting comments, other websites, etc.
› Good comments are usually pretty short, have a positive/constructive tone and are open to being contradicted by other readers.
› Good comments are always on topic and never contain spam or spam-like content.
› Good comments are rarely anonymous because contributors should feel able stand behind their opinions.