The Importance of Link Signals in Modern SEO

In the third decade of widespread internet usage, search engines like Google consider numerous factors when determining a website’s ranking.  With so many different things influencing search results, SEO engineers often wonder if the link-centered approach is still appropriate.  The answer? It is. 

According to a study by SEMrush, 4 of the 8 most important ranking factors relate to link signals.  These 4 factors are: total referring domains, total number of backlinks, total referring IPs, and total follow-backlinks.  Backlinko backs up these findings with a slightly different approach: according to their study, the average #1 Google organic search result has 3.8 times more backlinks and 3.2 times more referring domains than #2-#10.  Beyond the purely organic searches, nearly half of all Google searches have local intent.  And when it comes to local searches, a study by MOZ determined that link signals account for 28% of Google ranking factors.  That’s more than any other factor!  Despite these shocking statistics, 94% of all web content has no external backlinks, creating a missed opportunity for all the content involved.

So while the job of an SEO engineer has grown more complicated, the basics should not be forgotten.  Link building and technical optimization are still the most effective SEO tasks.  In setting up a search-grabbing website, one needs to adhere to the principles of a good link for today, tomorrow, and the foreseeable future.  

For those who aren’t well versed in the SEO field, what makes a good link?  The first thing to remember is that not all links are helpful.  The studies cited earlier implied that the more links a website has, the better.  However, Google’s quality guidelines prohibit deceptive links and strategies that don’t provide helpful content to users.  Sometimes to understand what makes a good link, one should eliminate the bad links first. One bad linking method is link schemes, which include buying or selling links that aren’t tagged as sponsored.  Another is hidden links that human users can’t find, either because they’re off screen or only linked to the page by a single character.  Also included in this category are doorway pages, or intermediary pages designed to rank highly for a specific search query only to funnel visitors to other, less relevant pages.

Beyond purely bad links, Google may also choose to penalize a website for “unnatural links.”  This category includes keyword-rich, hidden, or low-quality links embedded in a widget, widely distributed links in footers or templates of various sites, and forum comments with optimized links in the post or signature.  Simply put, Google does its best to reward sites that offer relevant content to visitors.  They don’t want to encourage websites to use dirty tricks on their climb to the top of a search query.

So how can a website make sure its links are of a high quality?  There are several elements that factor into a link’s quality judgement.  The first is anchor text, as excessive keyword optimization or high volume of exact matches in anchor text may be penalized.  Also consider the URL factors at play, as a high number of redirects or tracking parameters have the ability to degrade link quality.  Next, think about where in the website the link is located.  Links most likely to be clicked hold the most value.  The best, most valuable links should be placed in the body of a webpage while the least valuable links can be found in the footer, if one chooses to include them at all.  Finally, consider the distinction created by follow versus no-follow links.  Follow links offer more value because they vouch for the authority of the linked site.  No-Follow links are only likely to provide value with a high click rate because they don’t pass authority.  Be careful with this last factor.  SEMrush says that if one’s site ranks below the top 5 in a search, follow links are unlikely to make a difference.

Beyond the links themselves, one should consider page elements that might affect link quality.  With regards to outbound links (links taking a user away from a page), expert pages link to many high-authority sources on the same topic.  Links to these pages produce value.  Conversely, having too many poor quality links on your page creates a “bad neighborhood” in the virtual world.  Google doesn’t want to lead its users to a suspicious corner of the internet.  A high number of low-authority links lowers the page’s value.

The page elements of incoming links are also important.  The more high-authority pages link to one’s site, the more authority the page and domain appear to have.  In other words, the linking page will pass some of its authority onto the other site.  For this reason, high-quality links aren’t easy to get.  As Paddy Moogan, author of The Linkbuilding Book, says, “the harder a link is to get, the higher the value that link usually is.”  For a page determined to see long term success, links should be added slowly over time.  Good SEO is rarely an overnight success story.

Other page factors that matter when it comes to links are domain age, accessibility, and PDF links.  Links from new domains aren’t as high value, but they may grow more important as they mature.  On the subject of accessibility, the only links that matter are the ones search crawlers can see.  JavaScript, images without alt text, Flash, and blocked site links don’t boost rankings.  Finally, whitepapers and other PDFs can be crawled by search engines if available online.  Don’t discount PDFs.

Counterintuitive as it may sound to some, links are not the end all be all of link signals.  Qualities of the web page itself affect link signals too.  These qualities can be called a website’s link profile, and a good link profile is one that demonstrates trust, diversity (in websites), and relevance.  A major way to get more good links is to produce more good content.  Long-form content gets an average of 77% more links than short articles do.  While social media shares are helpful for exposure, social shares don’t always get links.  A good SEO engineer develops strategies for both link building and social media.  When it comes to competition, high-ranking sites need approximately 4x more referring domains for popular keywords than for the more obscure ones.  Finally, producing content that answers questions is often a good bet.  Content answering the why or what of an issue gets 26% more links than videos and how-tos do.

To sum it up, a gradual growth backed by quality and integrity is the key to superior link signals.  Fast moving schemes are not only limited in their success, but likely to induce penalties for one’s website. Bibi Lauri Raven, the founder of BibiBuzz, has this to say about links: “no website is an island.  As long as interconnected networks form the Internet, links matter.  They’re part of the logistics, the veins of Search.  But how these connections are created and valued can change.  So the only things that die at the moment are overused link-building tactics that signal an easy-to-spot, unnatural pattern.”  Avoid the trends of link building and focus on quality and content.  Everything else will fall into place from there.