Backlinks (also known as “inbound links”, “incoming links” or “one way links”) are links from one website to a page on another website. Google and other major search engines consider backlinks “votes” for a specific page. Pages with a high number of backlinks tend to have high organic search engine rankings.

 

What are backlinks?

For example, here is a link from Forbes to my website.

 

Forbes backlink

Because that link points directly to a page on my website, it’s a “backlink”.

Why Are Backlinks Important?

Backlinks are basically votes from other websites. Each of these votes tells search engines: “This content is valuable, credible and useful”.

So the more of these “votes” you have, the higher your site will rank in Google and other search engines.

 

Number of backlinks

Using links in a search engine algorithm is nothing new. In fact, backlinks formed the foundation of Google’s original algorithm (known as “PageRank”).

 

PageRank citation

Even though Google has made thousands of changes to its algorithm since then, backlinks remain a key ranking signal.

For example, an industry study that we conducted found that links remain Google’s key ranking signal.

 

Total external backlinks

And Google has confirmed that backlinks remain one of their three most important search engine ranking factors.

 

Search ranking factors

What Types of Backlinks are Valuable?

Not all backlinks are created equal.

In other words, if you want to rank higher in the SERPs, focus on quality backlinks.

Put another way:

A single quality backlink can be more powerful than 1,000 low-quality backlinks.

As it turns out, high-quality backlinks tend to share the same key traits.

Trait #1: They Come From Trusted, Authoritative Websites

Would you rather get a backlink from Harvard… or a random guy’s website?

As it turns out, Google feels the same way.

This concept is known as “Domain Authority”. Essentially, the more authority a site has, the more authority it can pass on to your site (via a link).

 

Domain authority

For example, here’s a link that I got from TechCrunch.

 

Techcrunch backlink

According to Ahrefs, TechCrunch is an extremely authoritative domain.

Because that link comes from an authority site, Google puts lots of weight on it. In fact, I noticed a boost in my organic search engine traffic right after TechCrunch linked to me.

Are these links hard to get? Definitely.

Are they worth it? Absolutely.

Trait #2: They Include Your Target Keyword In The Link’s Anchor Text

As a reminder, anchor text is the visible text part of a link.

 

What are anchor links?

In general, you want your links to have anchor text that includes your target keyword.

In fact, a recent industry study found a correlation between keyword-rich anchor text and higher rankings for that keyword.

 

Keyword rich anchor text

Now, a quick word of warning:

You don’t want to go overboard with keyword-rich anchor text. In fact, Google has a filter in their algorithm called “Google Penguin”.

Google Penguin filters out websites that use black hat link building strategies. And it specifically focuses on sites that build backlinks with exact match anchor text.

Trait #3: The Site (and Page) Linking to You Is Topically Related To Your Site

When a website links to another website, Google wants to see that the two sites are related.

This makes sense if you think about it:

Imagine you just published an article about running a marathon.

In that case, Google will put MUCH more weight on links from sites about marathons, running, fitness vs. sites about fishing, unicycles, and digital marketing.

 

Contextual backlinks

Trait #4: The Link Is a “Dofollow” Link

Google and other search engines ignore links with the “nofollow” tag attached to it.

 

Nofollow links

(In other words, nofollow links don’t count search engine ranking algorithms).

Fortunately, the vast majority of links on the web are “dofollow” links.

And most of the links that have the nofollow tag aren’t that valuable to begin with. For example, links from these sources tend to be nofollow:

These links aren’t super helpful for SEO anyway, so it’s not a big deal that they’re nofollow.

Trait #5: The Link Is From a Domain That Hasn’t Linked to You Before

Let’s say you get a link from Website A.

Great.

Well, let’s say Website A links to you again. And again. And again.

Are the 2nd, 3rd and 4th links as powerful as the first one?

No.