
Have you heard of the term "Backlinks" or "Inbound Links"? They has the same meaning. Backlinks are incoming links aka hyperlinks to your web pages. For example, if someone adds a hyperlink on their article which points to one of your blog posts, then he/she linking back to your page. Simply, it makes a connection with your blog. Usually, we mention a link in a blog, website, forum or whatever web page if it's important to the topic we have been talking or like to recommend it for visitors. Aren't we?
If many people sharing or mentioning that same link over and over again on different web pages, it convinces the page referred by that link has quite important content. So, if there are many backlinks for a post, article or web page, in this point of view, it has got a lot more attention of Internet users. Isn't it true? Bearing that thought, as search engines evolve on the web, the number of backlinks to a page has considered as an indication of popularity and importance of the content on that page. With this point of view and as Search Engine Optimization comes into play, Google has introduced PageRank, a link analysis algorithm, to measure and rank online web pages to serve Internet users better in searching the web.
Natural vs Unnatural Backlinks
As Google becomes more and more popular, Google's stuff got the attention. So PageRank. Businesses started to abuse this algorithm to show off popularity of their pages in different ways, expecting to grab attention of Internet users and bring more traffic for their sites. While users naturally linking to pages due to importance or relevance, some other parties started to assess the marketing effectiveness of this algorithm. So, online businesses started to bloom which offer paid backlinks for sites, to increase PageRank of their pages.
Someone else mentioning a link in a page is not the only way to create backlinks. We can create backlinks by sharing links on forums, submitting to article directories, while commenting if they accept links and so. But number of links is not the only factor which determines PageRank. Google has put more weight on backlinks which comes from high quality and popular sites. In other words, sites with higher PageRank. Assume you have 2 backlinks from a website with higher PageRank. Then it could be more effective on your site's PageRank instead of having 10 backlinks from a website with lower PageRank. It's one of top reasons that spammers trying to comment and leave links to their low quality sites expecting improvement on their site's PageRank.
Are We Responsible for Low Quality Backlinks?
Linking back to pages is super easy. Isn't it? If you haven't paid for backlinks, the natural backlinks you have are mostly created 'cause people loves your content. Else you have shared with someone on a forum to make use or left it with a comment. If you have been spamming around willing to get more link juice, selling or buying links, exchanging your links, submitting to lower quality directories or bookmarking sites, you are solely responsible of being affected by negative SEO due to violation of Google's quality guidelines.
But as anyone can link back to your pages, any spammy or low quality websites can link back to your pages without your knowledge. There's no restrictions for third party websites on creating backlinks to your site and you have no control over it. But Google take all of the backlinks into account when they evaluate your web pages with PageRank algorithm. Therefore you could lose your PageRank due to such spammy or low quality backlinks. It's a huge disadvantage for webmasters play by rules on the web. Eventhough you have no control over backlinks created by other parties, you had to be responsible for losing PageRank.
But as anyone can link back to your pages, any spammy or low quality websites can link back to your pages without your knowledge. There's no restrictions for third party websites on creating backlinks to your site and you have no control over it. But Google take all of the backlinks into account when they evaluate your web pages with PageRank algorithm. Therefore you could lose your PageRank due to such spammy or low quality backlinks. It's a huge disadvantage for webmasters play by rules on the web. Eventhough you have no control over backlinks created by other parties, you had to be responsible for losing PageRank.
A Way Out for Webmasters
Now Google has introduced a way to take control of backlinks negatively affected on your PageRank created by external parties. You can suggest spammy or low quality backlinks pointing to your blog, website, forum or any web page to Google through Disavow Links tool and ask them to ignore such backlinks when they assess your site for popularity. Eventhough you have been participated in link schemes and intended to manipulate site ranking, it's your second chance to keep away from them and start building quality links. Once you send suggested low quality backlinks, Google will evaluate them and determine whether they should assess or not, when determining PageRank or popularity of your pages.
When to Use...
Remember, it's not about asking Google to remove those links from spammy or low quality sources, but suggesting to ignore assessing them when Google assess your site's backlinks. Google's Disavow Links tool is not a simple tool to play with. If you haven't been participated in link schemes to rank your pages or your site isn't being negatively affected by SEO, you wouldn't need to use this one. If you believe that low quality sites linking to your pages and they have higher impact on your site's popularity, you can make use of this tool. First off, ask owner of the low quality site to remove links pointing to your site and if it doesn't work out, then you can make use of this tool.
Prior to request or send suggestions, you have to find out whether you have low quality links pointing to your website or not. Fortunately, my friend Lisa is being discussing about backlinks lately and she has shown the way to check out backlinks pointing to a website. Take some time to review your popular backlinks and if you believe there are backlinks that may strongly affect on your site's reputation and PageRank, take a note of them and proceed.
I think the video talking about Disavow Links tool will clear out if you have more doubts about it. Let's hear what Matt Cutts has to say about this tool and proceed with steps if you have found low quality, unnatural or spammy backlinks.
Prior to request or send suggestions, you have to find out whether you have low quality links pointing to your website or not. Fortunately, my friend Lisa is being discussing about backlinks lately and she has shown the way to check out backlinks pointing to a website. Take some time to review your popular backlinks and if you believe there are backlinks that may strongly affect on your site's reputation and PageRank, take a note of them and proceed.
I think the video talking about Disavow Links tool will clear out if you have more doubts about it. Let's hear what Matt Cutts has to say about this tool and proceed with steps if you have found low quality, unnatural or spammy backlinks.
Before You Go:
Once you identified spammy, low quality or artificial backlinks, you need to create a plain text file with a specific format including links before you submit them to Google. Just list all the links, line by line, as below,
http://www.spammysite.com/pagerank
http://www.spammysite.com/content01
http://www.spammysite.com/content02
http://www.spammysite.com/content03
http://www.lowqualitydomain.com/spam.html
http://www.artificial.com/spammy.html
http://www.spammysite.com/content04
http://www.spammysite.com/content05
http://www.spammysite.com/content01
http://www.spammysite.com/content02
http://www.spammysite.com/content03
http://www.lowqualitydomain.com/spam.html
http://www.artificial.com/spammy.html
http://www.spammysite.com/content04
http://www.spammysite.com/content05
If you have too many links from a single domain linking to your site, you can specify domain name instead of listing all the links. Take a look at above list of links and I'm gonna simplify it as below,
domain:spammysite.com
http://www.lowqualitydomain.com/spam.html
http://www.artificial.com/spammy.html
http://www.lowqualitydomain.com/spam.html
http://www.artificial.com/spammy.html
As you can see, I have specified spammysite.com domain, instead of individual links from that domain. Further, if you need to add a comment or note regarding some links you have listed, you can add them with preceding hash symbol (#) as below,
domain:spammysite.com
http://www.lowqualitydomain.com/spam.html
#Couldn't contact owner of the page to remove link
http://www.artificial.com/spammy.html
http://www.lowqualitydomain.com/spam.html
#Couldn't contact owner of the page to remove link
http://www.artificial.com/spammy.html
After listing all the links in a plain text document, save it and keep it to use in next steps. Make sure your file size is less than 2 MB and currently, Google accepts only one file for each site.
Steps:
1. Go to Google Disavow Links page.
2. Now select your website address that has spammy or low quality backlinks, and click Disavow Links button.

3. You will see a new page specific to your selected website and click Disavow Links button over there.

4. You will prompt to upload the file containing the links that you need to disavow. Click Choose File button and select the plain text file with links you have created earlier.

5. Now click Submit button to send your request over to Google.
Note: Google may take few weeks to re-crawl and re-index the links you have disavowed and evaluate, before they becomes effective.
More Information:
* If your site rank has been affected by low quality backlinks, after submitting links to disavow and they become effective, file a reconsideration request to Google to evaluate your site with Google's quality guidelines.
Enjoy :-)