Article Commentings...

We have heard about blog commenting is beneficial for getting back links but can some one have any idea about article commenting? Is it a good practice of commenting on articles to get backlinks?

Yes but if it is do-follow and you are using ethical and white hat technique to get backlinks, because every backlink can help you a lot to get good traffic as well as good ranking position in search engine.

How can one use black hat techniques in article commenting as it is just like blog commenting?

It depends. It happened so that I left comments by myself but it did no improvements.
So, I decided to use Paidforumposting.com commenting services. They have really good team of writers.
They helped me to increase the visitor traffic.
Believe that it will be reasonable info for you.

I think it is. It can also be a good help in your SEO campaign. If you'll be doing this one, make sure that you are putting your comment on do-follow article sites and high PR as well.

Article is one of the best and easiest way to get tbe beneficial link where  its provide link form the topmost sites and that top maost sites is for high page rank

Hello, article commenting is good but pretty much, because article sites commonly ignore your comment when you make and not approve. This is also hard to do and not beneficial than the blog commenting. So, i always prefer blog commenting to get backlinks.