Link building means earning hyperlinks that point to your site from other sites. Google has used them since its earliest days as a popularity signal: a link works as a recommendation, weighted by the trust placed in the site that gives it. That principle has not moved. What has moved is the tolerance shown towards links produced in bulk, and the speed at which a bad profile becomes a liability.
For a small business, the useful question is not "how many links should I buy this month" but "which sources will still be defensible in three years". Owning a website is ordinary; being cited elsewhere is not. One French benchmark gives a sense of scale, and it should be read as French data rather than a figure that transfers to the UK: the France Num barometer published by the Direction générale des Entreprises (11,021 small and medium-sized businesses surveyed in spring 2025, self-reported answers) found that 65% of respondents had a website presenting their activity.
What a backlink actually does
A backlink performs three separate jobs, each worth judging on its own. It passes a popularity signal to the search engine. It may send referral traffic you can see in your analytics. And it acts as a discovery path: a link on a frequently crawled page speeds up crawling of the page it points to.
What counts is not the raw number of links but the number of distinct domains citing you, how close they are to your subject, where the link sits, and the anchor text. Fifty links from one site are worth far less than five links from five sites that make sense alongside your business.
The study published by Ahrefs on 1 December 2023, covering roughly 14 billion pages from its own Content Explorer index, reports that 96.55% of them receive no organic traffic from Google. The scope is an SEO vendor's index rather than the whole web, and Ahrefs acknowledges a bias towards higher-quality content. The same study reports a correlation between referring domains and organic traffic.
The rules: what Google accepts, what disclosure requires
The Google Search spam policies name link spam explicitly: buying links or buying posts that contain links, excessive link exchanges, advertorials and guest posts carrying optimised links distributed at scale without editorial oversight, forum comments with optimised anchors, and links spread widely across footers.
The same document states that buying and selling links for advertising or sponsorship is normal commercial practice, provided the links are qualified. The documentation on qualifying outbound links assigns rel="sponsored" to paid placements, rel="ugc" to user-generated content and rel="nofollow" to other cases. Google states that links carrying these attributes are generally not followed.
<a href="https://example.com/" rel="sponsored">Paid placement</a>
<a href="https://example.com/" rel="ugc">User comment</a>
<a href="https://example.com/" rel="nofollow">Everything else</a>Two abuses formalised more recently bear directly on link building. Expired domain abuse is buying a lapsed domain mainly to manipulate rankings. Site reputation abuse is publishing third-party content on a host site mainly to exploit signals that host has earned. Both are still sold as services, and both sit outside the policies.
Disclosure adds a second layer that has nothing to do with rankings. UK advertising rules require marketing communications to be obviously identifiable as marketing, so a paid article should be labelled whatever its SEO treatment. French law puts the same duty in its consumer code. An unlabelled sponsored article is a compliance problem before it is ever an SEO problem.
| Practice | Status | Precaution |
|---|---|---|
| Editorial link given spontaneously | Within the policies | None |
| Occasional guest post, edited by the host | Within the policies if the scale stays small | Genuinely useful content, plain anchor |
| Paid placement or advertorial | Within the policies if qualified | rel="sponsored" and a visible advertising label |
| Buying followed links to move rankings | Link spam | Risk of devaluation or a manual action |
| Systematic link exchanges, partner pages | Link spam when excessive | Keep to genuine partnerships |
| Recycled expired domains, site networks | Outside the policies | Avoid |
The strategies that hold up over time
Publish something other people have a reason to cite
Link bait cannot be willed into existence: it needs an asset worth citing. Data only you hold, a simple calculator, a thorough guide, a local reference list. The pages that attract links are rarely commercial pages; they are reference pages. It is also the cheapest lever long term, because the links it earns do not stop when a budget stops. The work sits close to ordinary SEO content production.
Activate the relationships you already have
Suppliers, customers, trade bodies, chambers of commerce, sponsored clubs, local and trade press, serious sector directories: most small businesses sit inside a network that does not yet cite them. These links are legitimate and they last. They cost time rather than budget, which is why they are so often skipped.
Guest posts, at small scale
Writing for a third-party site still works when the subject interests that audience, the editor reads the piece, and the link sits naturally in the argument. What the spam policies target is industrial production of articles built around an anchor. The difference shows quickly: one link, a plain anchor, and a text that stands up without it.
Link exchanges, in moderation
An occasional exchange between two complementary sites, justified for the reader, causes no difficulty. It is systematisation, dedicated partner pages and large-scale three-way schemes that cross into spam. One test: would the link still be worth having with every search consideration removed?
What no longer carries weight
General-purpose directories, blog and forum comments, signature links and footer links duplicated across thousands of pages add very little now, and several appear in the link spam list. A few local or sector directories keep some value, mainly for visibility with customers.
Should you buy links?
The practice is widespread and the honest answer has shades to it. Buying a followed link to improve a ranking goes against the spam policies. Buying advertising visibility that is correctly labelled goes against nothing. Between those positions, many businesses buy sponsored articles while accepting a risk that rarely materialises immediately, which is what makes it easy to keep doing.
Three questions help settle it. What is left of your visibility if those links disappear the day you stop paying? Does the host site receive genuine organic traffic, or does it live on reselling articles? Would that budget do more as content, as relationship-led link building, or as a rebuild of the pages that convert? If the answer to the first is "nothing", you are renting rankings, not investing in them.
Assessing a site before you accept a link
| Criterion | Good sign | Warning sign |
|---|---|---|
| Organic traffic to the domain | Stable or growing, consistent with how much it publishes | Hundreds of articles, almost no traffic |
| Subject matter | Close to your activity or to your customers | Catch-all site mixing insurance, travel and DIY |
| The page carrying the link | Indexed, with an audience of its own | Orphan page created for the occasion |
| Commercial outbound links | Rare and contextual | Several sold links per article |
| Anchor offered | Brand, URL or a natural phrase | An exact commercial phrase imposed on you |
| Domain history | Editorial continuity you can verify | Expired domain revived on a different subject |
Proprietary scores such as authority ratings out of 100 are vendor estimates, not Google metrics. They help sort a list quickly; they do not make the decision. If you are comparing offers, the questions that matter are the ones you would ask when choosing an SEO provider for any other part of the work.
Pace, measurement and oversight
A link profile is built through regularity, not bursts. A monthly volume target pushes you towards the least demanding sources, because those are the only ones that can be delivered to a quota. Counting new relevant domains per quarter works better, even when the number is small.
On measurement, the Links report in Search Console remains the free reference, with known limits: the data is partial and sampled. Third-party crawlers fill in the picture, but each has its own index, which is why figures differ between tools. Compare trends, not absolute values. Setting new referring domains against the positions and traffic of the target pages is the only view that connects effort to outcome, and that is the substance of a backlink audit rather than a one-off count.
Finally, disavowal. Search Console help states that Google can usually work out which links to trust, and that most sites have no need for the tool, which is aimed at manual actions for artificial links. Check whether a manual action is reported in your account before building a file. Disavowing on suspicion removes links that were doing no harm.
Common questions
How many backlinks do I need to rank?
There is no universal threshold: the number that helps depends on competition for the query. Look at how many distinct domains cite the pages already ranking for that keyword, then aim for a comparable order of magnitude. On local or specialised subjects, a handful of relevant links is often enough.
Does Google forbid buying backlinks?
The spam policies classify buying links intended to pass a ranking signal as link spam. Buying advertising visibility remains acceptable when the link is qualified with rel="sponsored" or rel="nofollow". Separately, UK advertising rules require paid-for content to be identifiable as advertising.
What is the difference between nofollow, sponsored and ugc?
The attribute rel="sponsored" marks an advertising link or paid placement, rel="ugc" a link from content published by users, and rel="nofollow" other cases where you would rather not associate your site with the linked page. Google states that links carrying these attributes are generally not followed.
How long before a link has an effect?
The link has to be discovered first, which means the page carrying it has to be crawled, and that can take days or weeks. Any effect on positions is then judged over months, never link by link. No serious provider commits to a precise timescale.
Should I disavow low-quality links?
In most cases, no. Search Console help states that Google can generally determine which links to trust and that most sites do not need the tool, which is aimed mainly at sites hit by a manual action for artificial links. Check your account first.
Can I build links without a budget?
You can make progress with time rather than money, by asking suppliers, trade bodies, partners and local press that already know you to cite you. What a budget buys is speed.