How do backlinks work?

By Leon Tranter | SEO

Oct 26
how do backlinks work

You might have heard about backlinks, and been told how important they are for search engine optimization (SEO). Well they might not be quite as big as they were, but they are still very important for ranking your site. I’m going to tell you all about backlinks, what types they are, how they work, and nine powerful ways to get them. Let’s get right to it and find out how do backlinks work!

What are backlinks?

Backlinks are just links from a site from another site. If you want to get a bit more technical, a backlink is a hypermedia control (i.e. an <a> tag), with an href attribute that references another domain.

Backlinks versus internal links

how do backlinks work

It’s all about the backlinks…

The other main type of link is internal links. The difference between a backlink and an internal link is determined by the domain referenced in the href attribute. If an HTML document is served by a domain example.com and it includes hyperlinks, then any hyperlink with an href attribute involving example.com is an internal link, and any hyperlink with an href attribute of any other domain is a backlink.

So from the point of view of a webmaster, a backlink is a link pointing to your website from another website.

Why backlinks are important

To understand why backlinks are important, you need to understand the history of SEO and how Google’s search rankings really work.

In the very early (pre-Google) days of the web, links weren’t seen as important. Web pages were mainly ranked by keywords on the page. So if I had a page that said “dog training” a hundred times, it would rank higher than a page that said “dog training” once.

This seems reasonable but has huge problems. People just keyword stuffed and wrote stupid pages with keywords repeated and no meaningful content.

Keyword stuffing is bad m’kay?

Now nobody wanted to read those pages and nobody wanted to link to those pages. So Google came along with an idea. If a page had good content, people would want to link to it. If someone published a stupid keyword spammed article, nobody would link to it.

So they released the Google search engine, based on an algorithm called PageRank. This was a formula that ranked websites by their “trust” or “authority”, and this was mainly calculated by how many backlinks that page and website had.

So links could be thought of as “votes”, and the more “votes” something had, the more trustworthy it was.

It’s about pages and domains

As always, it’s a bit more complicated than that. A link is really a vote for two things: it’s a vote for the domain (“this is a good website!”), and a vote for the page (“this is a good page”). If a link is just to the website (i.e. to example.com instead of example.com/article), then it is just a vote for the domain.

If a website has lots of votes for its domain and/or lots of votes for all sorts of different articles on that domain, then Google sees it as a strong domain. If a website has lots of links to one particular article on that domain, then Google sees it as a strong page.

A strong domain will automatically infer some of its trust to all of its pages. If a page has lots of links but no other articles on that domain do, then that page will rank well but other pages will really struggle to rank.

Heard of Domain Authority and Page Authority?

This has led a search company called Moz to come up with two concepts: Domain Authority (DA) and Page Authority (PA). Now before I go any further, it is really important to understand this (this is really important). Nobody (except Google) knows how PageRank or any other algorithm in Google works. Nobody.

Anybody who says they do is lying. All we do is come up with theories. Google obviously keeps their engine a secret so people can’t game it. So Moz’s concepts and numbers come from Moz, not Google. It is their theory and their estimation. DA and PA are Moz concepts, not Google concepts.

Anyway, DA and PA took off as ideas and are widely used. Basically, these are numbers from 0 to 100 that rate a domain and a page in terms of how powerful Moz thinks they are in PageRank.

They are also logarithmic scales. So getting from 20 to 30 is not the same difficulty as getting from 10 to 20 – it is ten times as hard. And getting from 30 to 40 is ten times as hard again. So getting to 90 as all but impossible unless you are a serious titan.

A company called Majestic SEO came up with two other numbers called Trust Flow (TF) and Citation Flow (CF) which are similar but different to DA and PA. I don’t really understand how they work and they aren’t as widely used as DA and PA so I won’t go more into them.

Votes or juice?

So a link is a vote from one site to another site, right? Sort of… but not really.

Links are not created equally. Not at all. So a link is not binary, i.e. a yes or a no. It is more like a stream of water. That stream can be very weak or very powerful. People talk about “link juice”, and how much “juice” a link passes to another page. That’s a better metaphor than a vote, so let’s use it.

How link juice works

Google sees a link as passing some amount of trust or authority (or “juice”) from one place to another. How much juice is passed is based on a huge number of factors. But the biggest one by far is nofollow or dofollow.

Dofollow versus Nofollow

There are two kinds of links: dofollow and nofollow. By default, unless specififed as nofollow, all links are dofollow. So you won’t ever see “dofollow” on a link – that doesn’t mean anything. But some links can have rel=”nofollow” added to them.

Nofollow is basically telling Google “I just want people to be able to click on something and go to this place – I don’t necessarily endorse this website and please don’t take this link as me voting for it or anything”.

Nofollow links pass “negligible” link juice to the target page and domain. Having nofollow links is very important, especially in the era of web 2.0 and social media. If a link from a powerful site is seen as a huge vote for another site, then I could just go onto Reddit (which I think has a DA of 90 or so) and get a bot to create a hundred posts in a hundred subreddits with links to my website.

Or my Facebook page has a link to my website – should that count as a “link” from facebook.com to my domain? Of course not.

So pretty much every website where users create content will ensure that any links created are nofollow links. Otherwise the whole link system fails and we go back to the stone age.

But they don’t quite pass zero link juice. If a really great website came along and millions of people were suddenly talking about it on Reddit and Twitter and everywhere else, shouldn’t that count for something? Well it does – it’s just that each link counts for a very tiny amount.

There are way more link juice factors

So assuming we are talking about dofollow backlinks, there are still many factors that determine the strength of the link.

Nobody has an exhaustive list and nobody knows exactly how important each one of them is, but smart SEO nerds have put together a pretty clear picture based on decades of research.

Domain and niche

The most important is the domain authority of the site. A link from a DA 80 site is obviously a lot more powerful than a link from a DA 20 site. If Washington Post links to your blog, that’s obviously better than if your cousin’s six month old blog links to you, right?

The niche relevance is a major factor too. If my blog gets a link from a DA 50 website about digital marketing, Google sees that as a very positive signal, as compared to if my site gets a link from a DA 50 site about dog training. Google would probably see that as a mistake or a bought link, and might even penalise me. Google sometimes issues a dreaded “manual penalty” that can crush your website’s ranking.

Context is everything

It is also suspected that Google sees the text surrounding the link as important. If a link to my site is in a paragraph about digital marketing, that is a great signal. But if it is a paragraph saying “I had a nice holiday last month, had a really nice time – and I caught up my old college buddy, who has started a new blog (click here), I hope it goes well!”, then that is a different matter.

How strong is the linking page?

It’s not just the authority of the linking domain, but also the linking page. A link on an obscure page on Hubspot is going to be worth less than a link on a big pillar article with thousands of backlinks pointing to it.

This has led to some “link tiering” practices such as “link wheeling” and “link pyramids”.

Link tiering

If your page has a backlink from another domain, that is called a “Tier 1” link. Any backlinks to THAT linking page are called “Tier 2” links (and links to the Tier 2 pages are called Tier 3 links).

Due to the above rule about linking page authority, some SEOs focus not on building backlinks to their own domain (which is against Google’s guidelines, even using so-called “white hat” methods), but on building Tier 2 links.

You could then build out lots (and lots) of crappy social / web 2.0 links to those links. Thus creating a pyramid shape, which is known as a link pyramid.

link pyramid

A Link Pyramid involves building links to a site from pages, then links to those pages that link to you, then links to those pages.

Google can’t complain if I build links to other people’s websites – that’s literally the whole point of the web. And you will avoid sending low-quality links to your website – you send them to other people’s websites! So if Google decides those links are actually bad, it will have not much effect on your ranking.

So link tiering can be an effective way to boost the power of your backlinks.

Number of links on a page

Google sees each page as having a certain amount of total juice that it can pass on. Each new link reduces the amount of juice that the page can refer.

So if a page has a hundred links, each of those links will be much weaker than it would otherwise be (for that page and domain authority) if it only had ten links.

This change came about in the mid-2000s to penalise link farm sites that had web pages with thousands (or tens of thousands) of links. Even if those link farms manage to scrape together a decent authority, each link on that page would be worthless.

Don’t forget anchor text

I’ve written about anchor text. It’s such a complex and important topic that you should probably go read the whole anchor text article I wrote about it. But the super short version goes like this.

Google looks at anchor text very carefully. While it sees a link with keyword anchor text as a more positive vote for the page as having authority on that keyword topic, it hates to see a page with a huge number of links with the exact same anchor text.

It considers this to be evidence of spam or link buying, and could apply a large penalty. This was the main feature of the dreaded Penguin update of 2012 that obliterated a lot of black hat affiliate websites

And remember, Penguin might have been released in 2012, but it is still around today. Google does not have one algorithm, it has many. And they add to each other and work together.

The Penguin changes didn’t replace the Panda changes (their big update in 2011), it was added to it.

So now Google’s search results are modified by Penguin, Panda, Hummingbird, Mobilegeddon, Medic, and a host of others. Plus big new algorithm changes like RankBrain.

Types of link-building

So you want to get some backlinks (everybody does). There are many strategies for getting them. I’ll go through a few of the more popular ones.

Please keep in mind that while some people would consider outreach to be white hat and guest posting to be grey hat, in the eyes of Google, these are all black hat techniques (yes, even outreach).

Google does not want anybody doing any link building whatsoever. It wants all links to be natural, i.e. someone finds your website and decides they like it and creates a link to it.

So I cannot confirm or deny that you should use any of these techniques. They are all up to you and I cannot say you will not get penalized if you use any of these techniques.

Outreach

This is probably the safest and “whitest” of all techniques, though again, Google hates all link-building.

But basically, outreach is basically asking people nicely to link to your site. You write a good article, you email another website and say “hey check out my great article, I thought you might like it!”, and hope they link to it.

Obviously, this has a pretty low success rate. You can make it a bit higher by using Ahrefs or SEMRush to find similar articles to yours and going after the people who have linked to those articles. Make sure your article is way better than the one they are currently linking to!

This is what Brian Dean calls the “Skyscraper Technique”. Creating content that towers over everything else in the field (i.e. other articles are 2000 words, you write a 10,000 word article on the same topic). And hopefully people will want to switch their links from the 2000 word one to your one, once you let them know about it.

Moving Man Method

moving man method

Can you get free links with the Moving Man Method?

This is another technique that’s been around for a while but was named and popularized by Brian Dean from Backlinko. Rather than convince people to create new links to your site, or move links from an existing site to your site, you get people to move existing links from a non-existent site to your site.

If that sounds weird or stupid, bear with me. It’s actually a very simple and clever idea. Want to know how it works?

You find some website which is gone – dead, domain expired, company has gone out of business, taken over by hackers, whatever. That website would have some backlinks, right? And people linking to it probably don’t know it’s dead and wouldn’t want to be linking to it if they knew.

So once you’ve found your dead domain, make sure you have an article similar to the content on that site. You then check the backlinks with Ahrefs or SEMRush, and you reach out to all the people linking to that page.

You say “Hey, I’ve noticed you’re linking to deadsite.com – did you know they’re not around anymore? Anyway, I’ve actually published a good article on that topic. Maybe you can swap your link to mine?”.

This requires a bit of legwork up front to identify the dead websites but can be an easy way to get some links.

Guest posting

This is one of the oldest and most popular ways of getting links. You do a guest post on someone else’s blog, and they give you a link to your blog. Often, this link (if it’s from a decent site) is in lieu of payment for the article.

However, there’s a sneaky catch. This technique is starting to work less well than it used to. Want to know why?

I mentioned before about the context surrounding a link, and how Google takes that into account. But it’s not just the words in the sentences around the link. Google is getting smarter at understanding the semantic structure of pages and the semantic context of links.

What that basically means is regardless of the words in the sentences, Google can understand if a link appears in navigation, a sidebar widget, a popup, an article body, a footer, or an author bio.

And Google is now placing less weight on links that appear in author bio sections on a page – such as you would typically get when doing a guest post.

Now I’m not saying that guest posting is dead – nor am I saying that you should do lots of guest posting. All I’m saying is that the rules are changing and that guest posting is a less effective approach to linking building than it was a few years ago.

Paid links

There are a bunch of services now where you can just pay for a link. Somebody has a blog, they register their blog with a link building company.

Now I have a new website, I go to the link building company, and ask for a link. I pay them $100, they pay the blog owner $50, they keep the other $50, and he or she puts a link on their blog.

This is not the same as the infamous PBNs (Private Blog Networks) because the blog is owned by a third party. If the link building company owned all the blogs, that would be a PBN, which is the technique most hated of all by Google.

While Google doesn’t like paid links, they are much harder for Google to sniff out than PBNs, because they websites are all owned by different people.

Paid links are definitely a thing – they work if you want to get links. Although the content is usually of decent quality (unlike the shabby link farms of 2010), Google doesn’t really like them. And that’s simply because they want people paying money to them to get to the top of the SERPs via Adwords. Not paying some third party link builder.

Google has officially said they don’t like paid links and they will penalize people. How they will catch them out is another matter altogether.

At the moment, this is probably somewhere between grey and black hat link building, but the line is blurry anyway. Grey hat isn’t really stuff that’s half ok with Google and half not-ok, it’s more stuff that Google doesn’t really like but hasn’t yet figured out how to stop, and so hasn’t really cracked down on.

Web 2.0s are easy but kind of worthless

Web 2.0 sites like free blogs (wordpress.com, Weebly, Tumblr and so on) or social networking / social media sites like Reddit and Facebook and so on are easy for building links. Well, you don’t even have to build them, you can just make them.

But as I explained above, this makes a mockery of the whole link-building concept, so these links are all no-follows. You can make as many as you like. Each one passes “negligible” link juice to your site.

pillow link

You can use Web 2.0s for Pillow Links

Google kind of likes to see lots of them as a vague ranking signal (as opposed to a site with none or very few of them), but don’t expect great results.

Many people use Web 2.0s for pillow links (non-keyword links) to their target domain, or in a link tiering / link pyramid structure (linking to their Tier 1 links, to slightly beef up the link juice of the Tier 1 links).

Social signals are kind of good

Social signals can be nice. This is things like retweets, Facebook likes, Pinterest pins, and so on.

Google doesn’t really take these seriously link they do Dofollow backlinks, but like Web 2.0s, they see them as a positive sign.

Social signals and Web 2.0s can be useful for breaking your site out of the hated “Google Sandbox” that new websites find themselves in (an article for another day).

Question and answers

These are sites like Quora or Yahoo Answers, where people post questions and answers. Like Web 2.0s, these are weak nofollow links, though they are from high DA websites with huge amounts of traffic.

So they won’t be strong in terms of link juice. But don’t discount the actual amount of traffic you can get from them (see below).

PBNs, or Private Blog Networks

private blog network

Private Blog Networks are a collection of websites owned by one person

Now we get to the most famous and controversial backlinks of all: PBNs. This stands for Private Blog Network, and is simply a collection of websites owned by a particular party or individual.

Obviously, if I own a whole bunch of websites, I can create a link on any of them that goes anywhere. And I can pick the right niche, the right article, the right context, and the right anchor text. I can make the perfect link anytime I like. But Google doesn’t like that.

Google wants links to come “naturally”, i.e. to come from a third party, not from myself or a site I own.

Smart webmasters have skillfully built up collections of many decent authority sites without Google knowing that they are owned by the same person. This becomes a Private Blog Network and these can be enormously powerful in passing link authority.

Of course, it goes against Google’s wishes (and commercial interests!). Google is constantly on the lookout for PBNs and trying to sniff out the biggest ones. Every now and then they expose one and slap penalties on all the sites in and linked to by the PBN.

This causes a big ruckus and makes people run around complaining that PBNs don’t work, which is exactly what Google wants.

So should you use PBNs?

Again, I’m not going to tell you to do anything black, grey or even white hat, because Google hates all of it, even white hat link building. You might get busted, you might not. It’s ultimately your choice, your cost and your risk. I’m just here to tell you what your options are.

As with everything in life, there are pros and cons to be weighed up, and risks to be taken into account.

PBNs might work really well for you or they may be a total disaster. The decision and risk are yours to take.

But don’t forget what links really are

It is important to sometimes take a step back and remember what links really are: a hypermedia control that lets someone visit another hypermedia site. That is, something that somebody can click on!

Google sees them as a ranking factor, but they are less important than they used to be.

So just because Google doesn’t care about your link doesn’t mean it’s worthless. Somebody might actually click on the damn thing – which means traffic to your site!

Are links still important?

Google does still care about links. A lot. They are still considered to be one of the if not the most important ranking factor. But they are not the only one, by a long shot.

These days, Google is paying more attention to content quality, especially good long-form content packed full of LSI (Latent Semantic Indexing) keywords. Plus “behavioural” factors in the RankBrain algorithm that are neither on nor off-page – such as click-through rate and Time on Page / Dwell Time.

The importance of brand search

Google is also taking into account more esoteric factors such as, are people actually searching for your brand?

I might build russianhackerspr0ncasino.tk, and pack it full of a hundred 5000 word articles and buy a hundred thousand backlinks from the biggest and best PBNs in the world. But nobody is ever going to search for russianhackerspr0ncasino.

As opposed to my new cool startup, Affiliatrrr.io, which might only have 10,000 words on its site and no backlinks, but half of the cool tech nerds in Silicon Valley are Googling it every day. In which case, Google might rank it quite high, even though it is failing on traditional ranking factors.

This area is an interesting area where the lines between technical SEO and real world marketing / publicity are blurring.

Summary: all about backlinks

Well, I had no idea that this article was going to be such a huge beast when I started writing it. As you can see, backlinks are a massive and complex topic – and there are things I haven’t talked about and haven’t learned about.

I hope you learned a lot. There are so many different approaches to backlinks that it can be overwhelming sometimes.

The best advice when starting out I think is that which the guys from Income School (I’m not an affiliate of theirs, though they produce some exceptional content on Youtube) give: if you’re not sure, just don’t build links.

They will come. All by themselves. If you’re patient, and you just give them time, they will appear all by themselves. Whether you like it or not.

As always, please leave any questions or feedback in the comments below!