Backlinks and link building – what links are, how they are valued and how to build them

Definition

Backlinks are links from other websites to your own. They act as external signals that help search engines judge credibility, relevance and authority.

What makes a backlink valuable?

Backlinks have long been one of the strongest signals in SEO. The basic idea is simple: when another website links to yours, it acts as a vote of confidence. But not all backlinks are equal – quality and context are decisive.

The factors that most affect a backlink's strength:

• The source's authority – A link from an established website with a high domain rating carries more weight than one from a brand-new blog
• Topical relevance – A link from a page in the same subject area is stronger than one from an unrelated context
• Placement in the content – A link in the body text is more valuable than one in the footer or sidebar
• Anchor text – Descriptive anchor text helps search engines understand what the linked page is about

According to research from Ahrefs (2023), 96.55% of the pages in its index get no traffic at all from Google, and a lack of inbound links is one of the main reasons. Your link profile is still one of the most decisive ranking factors for competitive keywords.

Dofollow and nofollow – does it matter?

A dofollow link passes ranking value (link juice) to the linked page. It is the standard format for editorial links and what is traditionally meant by "backlink" in an SEO context.

A nofollow link (rel="nofollow") signals to search engines that the link should not be interpreted as a vote of confidence. It is typically used in comment sections, paid content and user-generated material. Since 2019, Google has treated nofollow as a "hint" rather than a directive – so such links can still have some effect.

Nofollow links from relevant, high-traffic websites can still deliver value through direct traffic and brand exposure.

How do you build backlinks?

Link building is the craft of systematically earning links to your website. There are no shortcuts that last – these are the methods that build a sustainable link profile:

• Digital PR – Create content, statistics or tools that journalists and industry blogs choose to refer to
• Guest posts – Write for relevant websites in your industry with a natural link back
• Broken link building – Find broken links on relevant websites and offer your own content as a replacement
• Linkable assets – Guides, glossaries, tools and statistics round-ups attract natural links over time

Buying backlinks – does it work?

No – not as a long-term strategy. Buying backlinks breaches Google's spam policies. At best, the bought links are ignored; at worst, they lead to a link penalty that drags down the whole website. The price of a "strong" link also reflects the risk the seller takes – not the value you get. If the damage is already done, the guide to Google penalties explains how to work out what has happened and when a disavow is justified.

The market exists because the demand is real: links affect rankings, and earning them properly takes time. But Google actively works against the practice. The SpamBrain system is trained to identify both websites that buy links and websites used to pass them on, and Google's link spam updates neutralise such links – they simply stop counting.

The honest advice: spend the budget on things that earn links instead. Linkable content – your own statistics, guides, tools – and digital PR build a link profile that lasts, without the risk. It is slower, but what you build, you get to keep.

How many backlinks do I need?

There is no magic number for how many backlinks a page needs. It depends on the competition in your SERP: look at the pages in the top 10 for your keyword – how many relevant linking domains do they have? That is the level to match, not the totals for entire domains.

Quality beats quantity. A relevant link from a website with high domain authority in your own industry carries more weight than dozens of weak ones. And count unique linking domains rather than the total number of links.

Use your competitors' link profiles as a benchmark. Tools such as Ahrefs show how many domains link to each page in the top 10 – that gives you a realistic picture of what your keyword requires. If your competitors have only a handful of linking domains, targeted link building can go a long way; if they have hundreds, content and strategy need to carry a larger share of the work.

Brand mentions – backlinks without a link

A brand mention is when your brand, company name or website is named on another website without a clickable link. Google's patented technology for understanding "implied links" suggests that such mentions can influence how search engines perceive your brand's authority, even without an actual hyperlink.

With AI, brand mentions matter even more. When an AI model is trained on web content, how often and in what context a brand is mentioned are among the signals that shape how the model perceives its position, expertise and relevance. Being mentioned on credible websites – with or without a link – therefore belongs in both your SEO and your AEO strategy.

Backlinks and AI visibility

Links still matter – but today they work alongside brand mentions, content quality and E-E-A-T. The link profile of the future is built as much by being cited in AI answers as by traditional inbound links.