Importance of Backlinks In SEO : Quality Backlinks

SEO is a process for rank a website higher in search engines.SEO is essential for all type of websites for better rank.I think SEO is the basic need for a website.SEO process further divided in to two categories that is ON page SEO and OFF Page SEO.In this post I am going you to explain about the Backlinks.Backlinks are comes under Off page technique.I think backlinks are the most important part of our SEO startegies.
What determines your position on search engine results pages (SERPs)? 
“Its not anything you put on the site, but rather how well you convince others to link to you.”
I am talking about only quality backlinks not about all links that your site have.Now a question comes in everyone’s mind that :
What is quality backlinks?
“A quality backlink is the backlink that is connect to your website using your keywords or a single keyword phrase.And the main thing is it needs to be appear on a website that have similar content topic like yours.”
I think quality backlinks helps so much a website to rank fast on search engines.Now I am going to discuss the techniques from where we can get quality backlinks.Some of these are as follows:
1.Article Marketing
2.Press Releases.
3.Guest Blogging.
4.Blog Commenting.
5.Link Exchange.
6.Blog Commenting.
7.Document Sharing.
8.Profile Links (High PR sites)
I am using all these techniques.But I like blog commenting technique so much.And I am going to explain this technique with you step by step:
Firstly we need to make query according to our search term.Suppose we need to find blog comments sites for “web design” keyphrase.Example of query for this search term: “web design” “Leave A Reply” “url” “[1..1000 comments]”
We can make many queries like this according to our requirement.We need to search this query on or any Google according to country.From this you can get all posts related to your topic.The another way which one I am using is this site you can search your topic in search box and you can get latest post related to your topic from all over the world.But keep in mind your comment would related to the post where will you do a comment.What do you think about Backlinks :Are they important or not? Please share your reviews in comments.