Like any other ‘minor’ link building – blog commenting is also useful. Because of how blog comment spam has arisen, the search engines are most likely to develop (or to be developing) ways to filter good comments from spammy ones.
So an important question arises: “If I build links via blog commenting – do I look like a spammer?”
To see how comment spam can be identified algorithmically, let’s try analyzing Spam Karma reports (it was only fooled once or twice with my own blog). The plugin uses combination of the following ‘red flags':
- It looks at the period of time the comment was posted after the page loaded;
- It analyzes if the comment contains an URL(s) in content;
- (If there is an URL in content) it compares non-URL comment length and the length of the URL itself;
- It looks if the URLs are linked or not;
- It filters some ‘spammy’ IPs;
- It looks how old the post is and how long ago the latest comment there appeared;
A search engine can do pretty much the same plus it might be looking into:
- comment relevancy;
- overall comment content length;
- similar/same comments around several blogs;
- your linked comments acquisition rate (e.g. 100 per day might look unnatural);
- some blacklist words like “porn” both in the author link and the
So if you avoid those flags and comment at relevant (established) blogs (that both follow and nofollow) you are both adding value to the discussion and doing some natural link building (btw, if you have a similar to the blogger’s post article, deep-link your author link).