The purpose of these guidlines was written with the "intent to forge a relationship, not to self promote." Not always easy to do, but worth a try.
1. Be specific. Personalized comments show authors that you’re genuinely interested in what they have to say, and that you actually took the time to read what they wrote. This doesn’t mean you need to write a long comment, just be sure to articulate why you felt compelled to say something in the first place. Did you learn something new? Did you have a similar experience? Do you want to voice a different perspective? Quote the author directly if you need to clarify what specific sentences you’re responding to.Thanks for your consideration.
Even if you simply want to compliment someone’s work, explain what you liked about it. Avoid vague comments like “Awesome! Thanks for sharing.” If you’re not sure what to say, consider using the Like button to show your support.
2. Don’t leave a link to your blog. When you leave a comment on a WordPress.com blog post, your name will automatically link to your blog, so there’s no need to include it twice. (This setting can be found under Users → Personal Settings in your dashboard, in the Account Details section.) Blatant self-promotion is generally frowned upon and is likely to be ignored, so be careful not to tarnish your reputation by creating the perception that you’re a spammer.
On a related note, when you mention another author’s post on your own blog, do include a link, instead of just mentioning the post title or blog name. This will generate a pingback and inform the author that you mentioned their post.
3. Stay on topic. Take care not to diverge too far from the subject of the original post. If you end up in an off-topic exchange with other commenters, message them directly to avoid distracting from the comments left for the post author.
It’s perfectly acceptable to share relevant links, just be sure to explain how they relate to the original post.
Bonus trick: Turn text into links with HTML by using the following code:
1. "http://wordpress.com">My favorite blogging platform
creates My favorite blogging platform when published as a comment.
4. Be nice. Even if you disagree with someone, it’s never appropriate to use insults or other offensive language. Rude comments don’t add any value to a discussion, and only divert attention away from the author’s work. It’s perfectly fine to offer constructive criticism, just be polite. If you see others writing disrespectful or incendiary comments, or you receive such comments on your own blog, ignore/delete them. Acknowledging them will only encourage the aggressor, so don’t waste your time.
5. Keep it brief. The more concise your comment, the easier it will be for others to read and respond to. In most cases, a few sentences is plenty.
But what if you feel strongly about a topic and have a lot to say — is it appropriate to leave a long-winded comment? Or should you write a response on your own blog, then leave a comment that summarizes your post?
It depends. Some bloggers feel that long comments are overwhelming and disruptive. Others prefer to keep the conversation all in one place.