We always wanted traffic for our site, wanted some good links and juices for our site. But we must be aware of many factors that affect the quality of our site. The do-follow and the no-follow.
Sites with do-follow links for their neighbor's url and visitors comment loves links, they appreciate good comment with relevant content and not a spam at all. However this sites are sometimes abused by spammers giving unwanted comments irrelevant to the content of the site. One blogger said he made his site a do-follow site however "I do get a few comments that I will NOT approve because they are obvious comment spam. " he said. So you must consider on what are you doing for this people may get tired of deleting this junks. We must appreciate their effort as a part of our community in the net.
I have found some rules in do commenting do-follow sites
1. Read the post you are going to be commenting on! Site owner also read several of the current comments if there are some. It only takes a few minutes to read the comments and get a general feel on what people are thinking.
Then, post comments directly related to the blog post, related to the general tone of the comments, or related to a comment left by a specific person.
2.Be kind, even if you disagree with the blog owner's post, or some individual comments. As a blog owner if you blast me or some of my posters directly, I won't allow your comments. If you disagree with me, that's fine. Disagree, offer more information to support your disagreement, and do it respectfully.
3. I prefer at least a short paragraph of comments, that adds to the comment conversation. A simple "I agree" is not going to be approved by me.
4.Don't use your comments to list every website you own. After leaving some good comments, don't blatantly advertise your other websites. I'm already giving you an incoming link with your selected anchor text. If you add additional websites, I probably won't approve your comments.