Why are backlinks important for SEO?

Few questions in SEO get asked more often, or answered more lazily, than this one. Backlinks have been at the heart of how search engines rank pages since Google launched on the back of PageRank, and yet every year someone declares them dead. The truth is more useful than either the hype or the obituaries. Links still matter, the evidence is consistent, and they now do something they did not do five years ago: they shape whether your brand appears in answers from ChatGPT, Gemini and Google’s own AI features. This guide explains what backlinks actually do, what the data shows, and why earned authority has arguably become more valuable, not less, as search splits across more surfaces. If you are weighing where to spend your marketing budget, the case for links is stronger and more measurable than most people assume.

What a backlink really signals

A backlink is simply a link from one website to a page on another. When a respected publication, a trade body or an industry blog links to your content, that link carries meaning beyond the click. Search engines read it as an editorial signal that someone found your page worth referencing. This is the idea behind Google’s original PageRank model, which assesses the importance of a page partly by looking at which other pages have, in Google’s own words on its philosophy page, been voted the best sources.

The voting analogy is helpful as long as you remember that not all votes count equally. A link from a national newspaper is not the same as a link from a forum signature or a scraped directory. Search engines weigh several things at once.

• Authority of the linking site. A trusted, widely cited source carries far more weight than an unknown one.
• Relevance to your topic. A link from a site in your field tells search engines more about your page than one from an unrelated corner of the web.
• Placement on the page. A link inside the main body of an article counts for more than one tucked into a footer or a signature.
• How the link came about. A link given on merit, inside real content, reads very differently from one mass-produced by a network of sites built for nothing else.

If you are new to the concept, our explainer on what backlinks are covers the mechanics in plain terms.

Crucially, links are difficult to fake at scale without getting caught. Google states plainly on the same page that no one can buy better PageRank, and it invests heavily in spam systems to keep that true. That difficulty is the point. A signal that is hard to manipulate is exactly the kind of signal a search engine wants to trust.

What the ranking evidence actually shows

You do not have to take the theory on faith. Several large studies have measured the relationship between links and rankings, and they point the same way. Backlinko analyzed 11.8 million Google search results and found that 3.8 times more backlinks at number one. The same study found that a site’s overall link authority correlated strongly with higher rankings, and that the number of distinct domains linking to a page tracked with where it ranked.

Ahrefs, working from one of the largest link indexes in the industry, reports a positive correlation between the number of websites linking to a page and both its ranking position and its search traffic. The pattern holds across enormous datasets, which is rare in SEO research. Our own campaigns line up with the research. Targeted link building produced 207% more organic traffic in six months for the client in our Breeze case study.

A fair word of caution belongs here. Correlation is not causation. High rankings can attract links just as links can lift rankings, and honest analysts, including the authors of these studies, say so. But when independent datasets of millions of results keep showing the same relationship, the sensible conclusion is not that links are irrelevant. It is that links remain one of the signals that separates pages competing for the same terms. If you want the full picture of how links fit alongside content and technical factors, our link building strategy sets it in context.

The four jobs a backlink does for you

It helps to stop thinking of a backlink as a single ranking lever and start seeing it as four benefits bundled into one. Each works on a different part of how search and discovery function.

• Authority and link equity. A link from a credible page passes a measure of trust, sometimes called link equity, to the page it points at. The more authoritative and relevant the source, the more weight that signal carries, and this is the part most people mean when they talk about links and off-page SEO.
• Discovery and crawling. Search engines find new pages by following links. A page with nothing pointing to it is far harder for a crawler to reach and index, so earned links from active, frequently crawled sites help your new content get discovered and indexed sooner.
• Referral traffic. Links are not only signals to machines. A well placed link in a relevant article sends real people to your site, and visitors arriving from a trusted, on-topic source tend to be more engaged and more likely to convert than cold traffic. That value exists whether or not the link moves a ranking.
• Topical relevance. The context around a link, including the anchor text and the topic of the linking page, helps search engines understand what your page is about and which queries it should answer. Links from sites in your field reinforce your topical authority in a way that off-topic links cannot.

A strong link tends to do all four at once, which is why a single editorial mention on the right site can be worth more than a long list of placements. Understanding the main link types makes it easier to see which of these jobs a given link is doing.

Why links still matter despite AI and algorithm changes

Google has spent years telling people not to obsess over link counts, and that is worth taking seriously. It is why this guide does not claim links are the single most important thing in SEO. They are not. Content that matches what the searcher wants comes first, because no volume of links will rank a page that fails to answer the query.

But there is a difference between overrated and unimportant. Google’s public documentation confirms that PageRank continues to be part of its core ranking systems. A signal that has evolved for more than two decades and still sits inside the core systems is not one you can ignore. Google’s message is better read as a warning against crude, mass-produced link spam than as permission to abandon earned authority altogether.

The arrival of AI features has not changed this foundation as much as the headlines suggest. Google’s AI Overviews and AI Mode are built on top of the same search infrastructure that already uses links, so the authority signals that help you rank in classic results carry into those experiences too. The honest summary is the one the largest datasets support: links are less of a magic bullet than they were in 2012, and more of a durable, hard-to-fake credibility signal that you neglect at your cost. For a deeper view of what separates a valuable link from a worthless one, see assessing link quality.

How earned media feeds AI answer engines

This is the part of the story that is genuinely new, and it strengthens the case for links rather than weakening it. As more people ask ChatGPT, Claude and Gemini instead of typing a query into a search box, the question is no longer only where you rank. It is whether you get cited in AI answers at all.

The most direct evidence so far comes from Muck Rack’s research. Its May 2026 edition analyzed more than 25 million links from ChatGPT, Claude and Gemini responses across 17 industries and found that earned media accounts for 84 percent. Journalism alone made up 27 percent of cited sources, while paid and advertorial content accounted for just 0.3 percent. Those figures have held between 82 and 89 percent across three editions of the study going back to mid-2025, which suggests it reflects how these systems source information rather than a one-off quirk.

The practical lesson is blunt. If your brand is not present in the credible coverage these models read, you do not appear in the answers they give. The mechanism is slightly different from classic SEO. When an AI system needs current information, it retrieves and cites trusted sources, and earned editorial coverage is what it leans on most. Building that kind of coverage is the heart of using PR for rankings, which has quietly become one of the most future-proof investments in the field, and the kind of link it produces is covered in naturally placed links.

Quality and relevance beat volume

If links matter, the tempting conclusion is to get as many as possible. That instinct is wrong, and the data explains why. Ahrefs found that 66.31 percent of pages have zero backlinks, and that 96.55 percent of all pages get no organic search traffic from Google at all. Two things follow. First, most of the web is not competing for links in any serious way, so even a modest number of good links can set you apart. Second, raw volume is clearly not what decides the winners, or far more pages would be ranking.

What separates a valuable link from a harmful one is quality and relevance. A single editorial link from a respected, on-topic publication can outweigh dozens of links from irrelevant or low-quality sites. Google’s spam systems are built to discount cheap PBNs, link farms, automated link building and mass directory submissions, and sites that lean on that kind of bulk spam risk penalties that cost far more than the links were ever worth.

This is why serious link acquisition looks more like earning coverage than churning out links. The earned editorial links, won because a journalist or an expert genuinely chose to reference your work, are the ones that pass authority and survive algorithm updates. The right question is not how many links can I get, but how few of the right ones do I need, a topic we cover in how many backlinks you actually need.

What this means for your strategy

Pull the evidence together and a clear strategy emerges. Links remain a core ranking signal, they do four useful jobs at once, and the earned coverage that produces them now also decides your visibility in AI answers. For a business owner or marketer deciding where to invest, that is an unusually strong case for treating link earning as a long-term priority rather than a one-off campaign.

The approach that works comes down to four habits.

• Create assets worth citing. Original data, genuinely useful guides or expert commentary give other sites a reason to reference you in the first place.
• Earn coverage for them. Outreach, digital PR and real relationships are what turn an asset into links.
• Favor relevance and authority over volume. A few links from sites your audience actually reads beat a long list from sites nobody visits, and they steer you clear of the shortcuts Google’s systems are specifically built to catch.
• Give it time. Results compound over months rather than appearing overnight, so treat link earning as a standing habit rather than a one-off campaign.

Local and B2B businesses can tune the same principles to their own market, as covered in links for local businesses and links for B2B brands.

It also pays to measure the right things. Rankings and organic traffic matter, but so do referring domains, the authority and relevance of your link sources, referral traffic from those links, and increasingly your presence in AI-generated answers. Tracking the work properly keeps it honest and shows where the returns are coming from, which is the focus of our guide to proving link building works. Done well, earned authority is one of the few marketing investments that strengthens your position in classic search and the AI answers that sit on top of it at the same time.