What is link building and why does it matter in SEO

Definition of linkbuilding

Linkbuilding —also written as link building— is the practice of acquiring hyperlinks from external pages to a given website. Those hyperlinks are known as backlinks or inbound links. From a search engine perspective, each backlink functions as a signal that another site considers the content it points to valuable or relevant.

The logic behind this principle is not arbitrary: when a site receives links from multiple external sources, search algorithms interpret that the content has recognition outside its own domain. That signal influences how the site ranks in organic search results.

It is important to distinguish linkbuilding from other related practices. Getting a low-quality directory to add a random link is not the same as building a link strategy. Linkbuilding as an SEO discipline involves planning: selecting relevant sites, defining the type of link being sought, controlling anchor text, and measuring the impact of each action.

Why backlinks remain a ranking factor

Google has confirmed on multiple occasions that links are one of the three main ranking factors, alongside content and RankBrain. While the exact weight of each signal changes with every algorithm update, backlinks maintain their relevance because they solve a problem that content alone cannot: demonstrating that other sites vouch for that information.

A backlink from a site with authority and topical relevance passes more value than dozens of links from domains with no track record or editorial context.

To better understand how that value is transferred, it is worth reviewing How PageRank works and its relationship with backlinks, which explains the mathematical model Google developed to quantify a page's authority based on the links it receives.

The mechanism has concrete practical consequences. A new site that publishes quality content may take time to rank simply because other sites have not yet linked to it. Conversely, a site with many relevant backlinks from established domains tends to gain visibility faster for competitive terms. This is not an absolute rule —content, user experience, and search intent also carry weight— but the pattern is consistent across markets as different as Mexico, Colombia, and Argentina.

Types of links and their impact on a strategy

Not all backlinks have the same effect on rankings. The attribute a link carries partly determines how the algorithm processes it. The two most common attributes are:

• dofollow: the search engine follows the link and transfers authority from page to page. This is the most sought-after link type in linkbuilding.
• nofollow: instructs the search engine not to transfer authority directly. This does not mean the link has no value —it can drive referral traffic and diversify the link profile— but its weight in terms of rankings differs from dofollow.
• sponsored: a specific attribute for sponsored content or advertorials. It was introduced by Google in 2019 so that sites could identify commercial relationships without needing to use generic nofollow.
• UGC (User Generated Content): applied to links generated by users in forums, comments, or collaborative platforms.

A detailed explanation of each, with application examples, is available in Types of links in SEO: dofollow, nofollow, sponsored, and UGC. Understanding the differences between these attributes is necessary before designing any campaign, as they affect both the acquisition strategy and how results are reported.

How a linkbuilding strategy is built

Linkbuilding is not simply about acquiring as many links as possible. A well-executed campaign starts with prior analysis and is guided by specific criteria of quality, relevance, and diversity.

Analyzing the existing link profile

Before going out to acquire new backlinks, it is worth auditing the ones the site already has. Tools like Ahrefs or Semrush allow you to see how many linking domains a site has, which anchor text types predominate, and whether there are toxic links that could be harming the profile. This diagnostic defines the starting point and prevents repeating mistakes in the new strategy.

Quality criteria for selecting sites

There is no single metric that determines whether a site is "good" for acquiring a backlink. The evaluation combines several criteria:

• Topical relevance: a link from a site in the same industry or with related coverage passes a stronger signal than one from a generic site.
• Domain authority: metrics such as Domain Rating (DR) from Ahrefs or Domain Authority (DA) from Moz provide an approximate reference for the accumulated authority of a site.
• Real organic traffic: a site with high authority but no traffic can be a sign of manipulation. Verifying that the domain receives real organic visits is part of the selection process.
• Domain history: sites with prior penalties or a history of bulk link sales can pose a risk to the link profile of the linked site.
• Geographic and domain diversity: for sites with a presence in LATAM, having backlinks from domains across different countries in the region can reinforce the local relevance signal.

The role of anchor text

Anchor text —the visible text that carries the hyperlink— gives search engines context about the content the link points to. A linkbuilding strategy manages anchor text distribution to keep it varied and natural. A profile with too many exact-match anchors targeting the main keyword can be interpreted as manipulation and lead to algorithmic or manual penalties.

Common acquisition tactics

There are several ways to acquire backlinks within a strategy. The most widely used in the Spanish-speaking market are:

• Sponsored posts (also called sponsored posts or advertorials): articles published on media outlets or blogs in exchange for payment, with a dofollow or sponsored link pointing to the client's site.
• Guest posting: articles written as editorial contributions on third-party sites, where the link is embedded as part of the content.
• Relationship-based linkbuilding: building connections with publishers, journalists, or content creators to earn natural mentions.
• Unlinked mention recovery: identifying mentions of the site on other domains that did not include a hyperlink and requesting that one be added.
• Link insertion in existing content: contacting sites that already have published articles and proposing the addition of a link to a relevant page on your own site.

Risks and ethical limits of linkbuilding

Linkbuilding exists on a spectrum that ranges from practices accepted by Google to techniques that explicitly violate its guidelines. The distinction matters because the consequences are asymmetric: manipulative practices may produce short-term results, but they expose the site to penalties that are difficult and costly to reverse.

For those who are beginning to explore the topic, White hat, grey hat, and black hat linkbuilding: differences and risks offers an analysis of each approach, including the criteria Google uses to identify them and the practical implications of each decision.

Among the most common mistakes made by those running campaigns without prior experience are the concentration of exact-match anchors, the purchase of bulk link packages from private blog networks (PBNs), and the lack of quality control over linking sites. Many of these issues recur across projects in different industries and countries. A practical review of these cases is available in Common linkbuilding mistakes and how to avoid them, which details how to identify them and what steps to take to correct them.

What to expect from a well-executed linkbuilding strategy

Linkbuilding does not produce immediate results. Search engines need time to crawl new links, process them, and reflect their impact in rankings. In highly competitive projects, that process can take weeks or months. Setting realistic expectations from the outset is part of managing the process professionally.

A well-executed strategy aims to build a link profile that is diverse, relevant, and sustainable over time. That means not only acquiring backlinks, but also monitoring the existing profile, identifying lost or toxic links, and adjusting the anchor text strategy as competition in the SERPs evolves.

Linkbuilding is a component of off-page SEO, not a substitute for on-page work or content. Its effectiveness depends on the site receiving the links having a solid technical structure, content worth referencing, and a user experience that retains visitors arriving through organic traffic.

For teams looking to professionalize this practice without building internal capacity from scratch, the team at Contenido Patrocinado covers linkbuilding campaigns in LATAM, with a focus on editorial quality and result traceability.