Do comments from blog act as back links?

I think comments in Blog could be considered as traffic rather than backlinks... but still depends on the one who add a comment on a blog =)

It considered a backlink if you provide your url in commenting other post.

I have 2 blogs and I believe that all of the comments that have links in the name are counted as back links.

There are many bloggers though that take the links out if it seems like you only commented to get the link. Also leaving a link in a comment can be considered spam by some also.

I still think the best way to get back links on blogs is to contact the blog owner themselves and ask for a review.

I tend to say that comments and the way you respond to comments can potentially affect your blogs popularity. People like to know that their comments are being listened to. Also it provides more material for search engines to spider and thus serve in their results.

hope it helps

You are right! I am agree with you.
Best of luck!