Yes, I Like blog commenting because it also gives me back the favor. People read me. If you comment on blogs regularly, they will the urge/need to comment back on your blog, too.
Yes, if carried out as part of a wider link building campaign. When commenting, ensure to vary the username and only comment on 'on topic' articles with keyword in title tag. Don't over do it. 2-3 a month is enough for one keyword.
Sure, if you go nuts and post to thousands upon thousands of blogs at once. (And point all of the comments to your money site.)
I guess Blog comment is SPAM, Because every people do blog comments with view to increase back links. As per my experience I hardly find such blogs which have some useful comments on their articles. So, the method of getting link juice through blog comments must be stopped.
For linkbuilding - Blog commenting is considered the lowest quality of backlink. It is can however drive traffic to your site. If you write catchy comments on high traffic blogs, it can drive traffic back to your site that can later on convert to sales or ad clicks.
Hey Guys well i think that blog commenting is really good for increase the ranking of any site.Thanks!!