Link building techniques have been used and abused since the very beginning of search engines, and while Google has been in a constant battle to prevent websites from manipulating its search results through acquiring unnatural links, a lot of ground has been covered in recent years, particularly with the release of its spam fighting algorithmic update, codenamed ‘Penguin’.

This makes it even more important to stay up-to-date with the latest link building techniques, especially as many of the overused methods that previously sat in a bit of grey area have since moved over to the dark side. These should definitely be removed from your past and future efforts.

Know your backlink profile

All new links should be future-proof, so before we start looking at some of the great ways to build links naturally, it’s important that we cover the old, questionable (black-hat) techniques. This will help you be more aware of the areas you need to steer clear of when developing link building strategies.

It’s very possible that a former in-house SEO or digital marketing agency was caught up in bad link building practices in the past.

Negative SEO

In some rare cases, sites have even been subjected to ‘negative SEO’ campaigns, which are designed to damage rankings by pointing low quality links to a website in an attempt to have it penalised by one of Google’s algorithms for violating its guidelines. Your website may already have been hit by one of Google’s algorithm updates. If this is the case, you have some cleaning up to do.

These damaging links could still be lurking in your backlink profile, so the first steps when planning all link building strategies should be to understand what efforts have already been made and where your existing backlinks come from. Then you can implement a plan to remove any suspicious or low quality links.

Downloading your backlink data

With the help of Google Search Console (formerly Google Webmaster Tools), you can download details of every web page that links to your website (Search Traffic > Links to Your Site). There are various tools that can be used to analyse your backlinks to identify which ones are considered as high risk, helping you to make the call on whether to remove them. However, in many cases a simple scan of the linking website is enough to get a feel for whether the website is of low quality.

Worst offending Blackhat link building techniques

There are too many blackhat techniques to list in one post, so below is a list of the most commonly used.

Article Marketing

This is something that most SEOs were involved in at some stage or another, including a number of big brands. The process consisted of creating an article containing links back to a website, then the distributing the same article to hundreds of article websites, which were set up with the sole purpose of harvesting backlinks.

Google launched the Panda algorithm in 2011, which was designed to downgrade low quality websites and prevent them from passing value through links. This marked the beginning of the end for article distribution websites, which created a huge ripple effect and caused many of the websites involved to lose significant amounts of traffic.

If you find links to your website from duplicate content across article distribution websites and can get hold of the login details for the sites in question, the best thing you can do is delete the articles. Failing that, you can contact the website (keep a record of communications in case you need it as part of a reconsideration request for a manual Google penalty), and last resort you should add the linking domains to your disavow file.

Buying or selling links that pass PageRank.

Paid links include links that were added in exchange for payment in the form of goods, services, or indeed money.

While in some cases Google is unable to know for sure whether a link was paid for, there are often many tell-tale signs, for example a ‘sponsor’ form, which outlines costs for listings.

Google also relies on the competitive nature of businesses to report websites who are buying links via its reporting form in Google Search Console.

Paid links are fine to use, so long as they include the nofollow tag, which prevents value from being passed and therefore removing any SEO benefits.

Excessive link exchanges

Another old-school favourite is the reciprocal link. This is based on the old ‘I’ll link to you if you link back to me’ concept, just for the sake of SEO gains. It used to be very common to have a ‘links’ page, full of links to random websites that would in turn link back to you. Some well known SEO tools would even provide a service to help manage these links, recording information as well as tracking them to make sure none were removed.

Google added this type of linking to its blacklist in its guidelines, so if you still have reciprocal links in place, it’s time for them to go!

Large-scale guest posting

While guest posting is by no means something to completely avoid, some websites continue to write low quality guest posts on low quality websites in order to include keyword-rich anchor text links.

Matt Cutts addressed this issue in his video ‘The decay and fall of guest blogging for SEO‘ is January 2014, where he advises anyone still using low quality guest posts to build links to stop.

Advertising banners and advertorials that pass PageRank

This includes banners with embedded links, as well as sponsored posts that link to websites without the use of the no-follow tag.

Low-quality directories & bookmark sites

In the early days of the internet, directories did the job of the search engines, helping users to find websites which were ordered by category. When Google began using links as a ranking signal, lots of new directory websites started appearing, but most of them were only created for link building purposes. In many cases they would charge a fee to be listed, so this made them even bigger targets for Google’s spam fighting algorithms.

Directory listings are still important, particularly for local SEO, but stick to directories that are relevant to your industry or location and avoid low quality directories at all costs!

Some directories require payment to be listed. The general rule of thumb is that if the fee seems fair in terms of the time of admin required to add the listing, then this should be fine. However, if any mention of PageRank or SEO gains are being used as a selling point, then you know what to do (or rather not do).

Keyword-rich links from widgets

Some widgets can be very useful, but they often include sneaky links that pass PageRank and in the worst offending cases, these links include irrelevant exact-match anchor keywords. If you’re planning to build a widget, by all means give yourself the credit using a link, but as Matt Cutts recommends in a video explaining how to link from widgets, consider adding the no-follow tag to your links. If you’re dead set on allowing the links to pass value then at least be sure to avoid linking from anchor text keywords.

Blog/Forum comments

Another common black-hat practice is building links from comments in blog posts or forums. These are often optimized links that are added to a comment or from the signature section.

Some spammers take this to the next level by spinning comments in an attempt to make them unique. The comments are fired out across every blog that they can find, while keeping the comment generic enough to catch out some unknowing bloggers.

Comment Spinning spam

They say in life “flattery gets you everywhere”. This is how many of the spammers manage to slip through the net, commenting on how well your post was written and how useful they found it.

Google Algorithms

If your website has been given a manual penalty by Google, you will be able to find details of this in your Search Console account (Search Traffic > Manual Actions).

However, algorithmic penalties are much harder to spot. You should be able to get a feel for whether your website was affected by Google’s Penguin or Panda updates using the data from your Google Analytics account. Dig into your organic traffic data then check for any significant shifts around the dates that the algorithms were released. Below is a list of some of the main Panda & Penguin updates, including the most recent Panda 4.2, which Google has said will slowly roll out over the next month.

Panda 1.0: February 23, 2011
Panda 2.0: April 11, 2011
Panda 3.1: November 18, 2011
Panda 4.0: May 19, 2014
Panda 4.1: September 23, 2014
Panda 4.2: 18 July 2015

Penguin 1.0: April 24, 2012
Penguin 1.1: May 25, 2012
Penguin 3.0: October 5, 2012
Penguin 2.0: May 22, 2013

Penguin 2.1: October 4, 2013
Penguin 3.0: October 17, 2014
Penguin Everflux: December 10, 2014

If you spot a pattern where your traffic losses coincide with one or more of the dates above then it’s time to take action, removing low quality links for a Penguin related penalty and reviewing your content (and links from sites with low quality content) for a Panda penalty.

Check out our guides for recovering from a penguin penalization and how to disavow links. The next Penguin update is due to be released in the coming months, so if you have been affected then now is the time to start your recovery efforts.

Are your competitors still being rewarded for black hat SEO? Share your experiences in the comments below.