Link Building

The core problem the Link Building layer solves is: getting other websites to “vote” for you. Search engines treat a link pointing to you (a backlink) as a vote of trust—if someone is willing to cite you, it means your content is worth citing. In the overall SEO workflow, link building is “Off-Page” work that sits on top of the content layer: content is the product, links are the channel. It directly affects a site’s authority and is the key variable that decides ranking order among similar, homogeneous content. You can think of it like academic papers—the more often you’re cited, and the more authoritative the citing parties are, the higher your “impact factor.”

⚠️ Note: Links are an “amplifier,” not an “engine.” For pages with poor content, links will only expose the problems faster. Always have content worth citing first, then push hard on links.

Link Fundamentals

• DoFollow vs NoFollow: By default, links pass authority (commonly called link juice); links with rel="nofollow" don’t pass it (or pass it weakly). Developers can see the difference at a glance—it’s just an attribute on the <a> tag:

  <a href="https://you.com" rel="nofollow">普通引用</a>
  <a href="https://you.com">传递权重的引用</a>

  There are also rel="sponsored" (paid/advertising) and rel="ugc" (user-generated content, such as comments), used to declare the nature of a link to Google.

• Anchor Text: The clickable text on a link, which tells search engines “what the linked page is about.” Keep it natural and varied—don’t use the exact same keyword every time.

• Relevance: A link from a site on the same topic is worth far more than one from an unrelated site. A baking blog linking to your SEO tool is far less effective than a tech site doing so.

• Authority: Links from high-reputation, high-traffic domains are worth more. One authoritative backlink often beats a hundred spammy ones.

Link Metrics

• Domain Rating (DR): Ahrefs’ domain score, 0–100, measuring the backlink strength of an entire domain.
• Domain Authority (DA): Moz’s equivalent metric, with similar logic. Both are third-party estimates, not Google’s official data—use them only for side-by-side comparison, and don’t obsess over them as a KPI.
• Link Velocity: The rate at which new backlinks are gained. Organic growth is a good signal; a sudden overnight spike of hundreds of links looks like manipulation and can easily trigger scrutiny.

💡 Tip: When sizing up a link opportunity, the rough priority order is “Relevance > Authority (DR/DA) > Quantity.”

Link Building Tactics

Tactic	One-line description
Guest Posting	Contribute articles to relevant sites, naturally including your link in the text
Resource Pages	Find “recommended tools/resources” pages and ask to be listed
Broken Link Building	Find a dead link on someone’s page and suggest replacing it with your same-topic content
Skyscraper	Find good content that already has many backlinks, make a better version, then pitch it to the citing parties
Digital PR	Produce newsworthy data/reports that get covered and cited by the media
HARO	Answer reporters’ questions as an expert in exchange for a bylined link

• Prioritize tactics that are “scalable without crossing the line”: broken link building and resource pages have a low barrier to entry, while Digital PR has a high ceiling.
• 🧑‍💻 Developer’s view: Many steps can be scripted—use a crawler to batch-collect candidate pages, run HTTP status code checks on outbound links to find 404s, and pull DR/DA via API to filter—leaving the human effort for writing outreach emails and negotiating partnerships.

Risk Avoidance

• Spammy Links: Forum spam, automated comments, low-quality directories—almost worthless, and harmful in bulk.
• Paid Links: Buying links that pass authority violates Google’s guidelines. Paid links must be marked with rel="sponsored".
• Link Farm: A cluster of sites that bulk-link to each other purely to manipulate rankings—a classic cheating pattern.
• Google Penalty: This can be an automatic algorithmic demotion, or a manual penalty (Manual Action, which you’ll be notified of in Search Console). At best you lose rankings; at worst you get removed from the index.

⚠️ Note: The test is simple—“If Google didn’t exist, would you still want this link?” If the answer is “no,” it’s most likely a risky link.

Internal Linking

• Passing authority: When pages within a site link to each other, you can “funnel” the authority accumulated by your homepage/high-authority pages to the pages you want to push up the rankings.
• Use descriptive anchor text: The anchor text of internal links can more explicitly include the target keyword, helping search engines understand the page’s topic.
• Build topic clusters: Use one “pillar page” to tie together multiple sub-articles, linking them to each other to form a structure.
• 🧑‍💻 Developer’s view: Internal linking is entirely within your control—no need to ask anyone. It’s the highest-ROI “link building” there is—it never crosses the line and can be deployed immediately.

📌 This Layer Is Under Construction

The full tutorial is still being written. The quick checklist below will help you put the most critical actions in place first.

✅ Quick checklist:

• Only start link building once the content layer is up to standard (have citable pages first)
• Chase links for “relevance + authority” rather than pure quantity
• Check the rel attribute on links: mark paid links as sponsored and UGC as ugc
• Use scripts to batch-detect broken links and scrape candidate pages, leaving the human effort for negotiating partnerships
• Sort out your internal link structure first (pillar pages + topic clusters)—this is a zero-risk boost
• Stay away from buying links and link farms, and regularly check Search Console for any Manual Action