I think you will be fine if you make sure you are...

1. Posting on blogs that have nofollow turned off (meaning they DO follow links).
2. You are making actual relevant posts (not spammy things like "Cool article!").
3. You do not use your keywords in the title (unless it is a personal site and you are trying to rank for your name).

As long as you do that you should get some decent quality back links from content pages. They will not be specifically helpful to any keyword but will help your overall value by google. Following the three rules above, most blog owners will be happy you contributed.

Good luck -John

Blog comment do also help in building reputation for a blog..considering that comments are not intended to be a spam...

It would give reputation if the comments are useful not just links . . .I have blog that users usually post links in all of their comments. . .

I think blog commenting is the best way to get backlinks. Try to comment in a variety of blogs over a peroid of two months.

Originally Posted by Learning Newbie

A wise man once said that links aren't optimization, and he was right.

haha, we all know who you are talking about.
wise man at times, thread killer at other times. depends on the mood.

Google does reward the blog owner when comments are made it is considered fresh content. How long the comment has to be to get noticed is up for speculation.

Originally Posted by Learning Newbie

The benefit of commenting on a blog post is that

1. you contribute your voice to the conversation
2. other people respond to your comment, helping you figure out if you're right or not, and what might need to be changed
3. you're showing the person who writes the blog that their ideas are being considered, and that their work (writing) is appreciated.

I have to agree with this, in addition to that SEO will also benefit in endorsing their client's site..

Ask yourself if the blog owner and the readers would be happy with your comment. If they are, you might just get direct traffic from them as well

I sometimes try to comment on .edu blog and its really effective to my site.

Your comment posting shouldn't be a method of link building. If you do post useful comments, u can build reputation among the industry and u can drive good traffic thro' that.

comment posting will help the the person who comments, if he is allowed to put a link from his site