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Links, authority and digital PR

In this lesson

Section titled “In this lesson”
  • Explain how links from other sites help a page rank, and why not all links count the same.
  • Choose the correct rel value for paid, affiliate, user and untrusted links.
  • Read Domain Authority, Page Authority, Trust Flow and Citation Flow, and know what they do not measure.
  • Compare the main ways to get links, and tell which ones break Google’s rules.
  • Plan a small digital PR or influencer campaign, and pick a tool to manage the outreach.

Until now, this topic was about your own site. This lesson is about the rest of the web: what other sites say about you with their links. Day 06b continues with brand signals that do not need a link.

Section titled “Why links matter”

A backlink is a link from a page on another site to a page on your site. Search engines read a backlink as a kind of vote: someone outside your site thought your page was worth a link.

This idea is old. In 1998, Google’s founders described PageRank in their research paper. Academic papers count citations to judge a paper. PageRank does the same with links, but with two changes:

  1. A link from an important page counts more than a link from an unimportant page.
  2. A page splits its vote over all its links. A page with 100 links gives each link less than a page with 2 links.

The paper gives a formula with a “damping factor” d, usually 0.85. You do not need the formula. You need the two rules above, because they explain most link advice.

Is PageRank still in use? Google’s guide to its ranking systems says that PageRank “has evolved a lot” and “continues to be part of our core ranking systems”. But the SEO Starter Guide adds a limit: “there’s much more to Google Search than just links”, and PageRank is “just one” of many signals. So links matter, but they do not replace good content from day 05.

Toy model with example data, using the formula from the 1998 PageRank paper. Add the news link, then mark it nofollow. Then move the slider. Notice that one link from a page with few links adds more than a link from a crowded directory page.
Section titled “What makes a good link”

The toy model shows only authority. Real link value has more parts. Ahrefs’ link building guide lists five:

Part The question to ask
Authority Is the linking page important, with good links of its own? Is the link free of nofollow?
Relevance Is the linking site about a related topic?
Anchor text Do the link words describe your page?
Placement Is the link in the main text, where people click it, or in a footer?
Destination Does the link go to your home page, a content page or a product page?

Authority and relevance matter most. One link from a respected site in your field is worth more than many links from unrelated sites. Placement is less certain. SEO writers discussed a Google patent in 2010 with a “reasonable surfer” model. In it, links that people are more likely to click pass more value. A patent does not prove that Google uses the idea, so treat it as not confirmed.

Anchor text

Section titled “Anchor text”

Anchor text is the visible, clickable text of a link. Day 04b covered anchor text for your internal links. For backlinks, the other site chooses the words.

The 1998 paper already used anchor text. It says that anchors “often provide more accurate descriptions of web pages than the pages themselves”. Google’s link documentation today says the same: anchor text “tells people and Google something about the page you’re linking to”.

SEO tools sort backlink anchors into types:

Type Example for a page about a backlink checker
Exact match “backlink checker”
Partial match “a free tool to check backlinks”
Branded “Ahrefs”
Naked URL “ahrefs.com/backlink-checker”
Generic “click here”, “this article”

A natural backlink profile has mostly branded, naked and generic anchors, because that is how people link. Many exact-match anchors look made. Google’s spam policies name “links with optimized anchor text in articles, guest posts, or press releases” as link spam. Ahrefs says that such anchors were a main target of Google’s Penguin update in 2012. Since 2016, Penguin is part of the core systems and “devalues spam” links instead of demoting the whole site.

Section titled “Link attributes: nofollow, sponsored, ugc”

Some links must not count as a vote. The rel attribute on the <a> tag tells Google why. Google’s “Qualify your outbound links” page defines three values:

Value Use it for
rel="sponsored" Ads and paid placements, including affiliate links.
rel="ugc" Links in user-generated content (UGC), such as comments and forum posts.
rel="nofollow" Any other link that you do not want to vouch for, when no other value applies.

Some history explains the three values. nofollow came first, in 2005, to fight comment spam. In September 2019, Google added sponsored and ugc. At the same time, it changed all three values into hints: Google can choose to use the link anyway. For crawling and indexing, nofollow became a hint on 1 March 2020. Day 03 showed what this means for your own pages.

These rules matter most for paid links. Day 02 showed that a paid link that passes ranking credit is link spam. Google lists “sending someone a product in exchange for them writing about it and including a link” as one example. The fix is simple: mark the link sponsored or nofollow. Google prefers sponsored, but treats both the same for this purpose. In a 2021 post, Google also asked affiliate sites and sites with sponsored or guest posts to qualify those links.

You can combine values, for example rel="ugc nofollow". For links from forum members with a long record of good posts, Google says that you can remove ugc.

The rel value on the link

Pick a situation on your site, then try each rel value. Notice that a missing value on a paid link is the only real risk. The other wrong choices still work, but they are not the best fit.

Authority metrics

Section titled “Authority metrics”

Google does not show how much authority it gives a site. So SEO tools build their own scores from their own link indexes. The four in the roadmap come from two companies.

Metric Company What it measures Scale
Domain Authority (DA) Moz How likely a whole site is to rank, compared to other sites 1 to 100
Page Authority (PA) Moz The same, for one page 1 to 100
Citation Flow (CF) Majestic Link “power”, based on how many sites link to a URL 0 to 100
Trust Flow (TF) Majestic Link quality: how closely a site links to trusted seed sites 0 to 100

Moz says that DA and PA come from a machine learning model. The model looks at linking root domains, link quality and other signals that correlate with rankings. Majestic builds Trust Flow from “trusted seed sites” that people reviewed by hand. Ahrefs has similar scores, Domain Rating (DR) and URL Rating (UR). Ahrefs says that a linking site splits its rating over all the sites it links to, as in PageRank.

Three facts matter most when you read these scores:

  • They are not Google’s scores. Moz says it plainly: DA “is not a Google ranking factor and has no effect on the SERPs”. Google’s John Mueller has said many times that Google does not use DA. In 2020 he said: “We don’t use domain authority at all in our algorithms” (as reported by Search Engine Journal). In a 2020 interview, he also said that Google has “some metrics that are more on a site level”. So Google may have its own site-level signals, but the third-party scores are not them.
  • They are relative and logarithmic. Moz says it is much easier to grow from 20 to 30 than from 70 to 80. A score can drop when other sites gain links. There is no “good” DA, only better or worse than your competitors.
  • The gap between two scores tells you more than one score. Majestic draws Trust Flow and Citation Flow together. A site with a high Citation Flow but a low Trust Flow has many links, but few from trusted sites. That is a warning sign for a link that you want to get.

Use these scores to compare sites and to sort link prospects. Do not make a higher score the goal of your work.

Section titled “Link building”

Link building is the work of getting other sites to link to yours. Ahrefs’ guide groups all methods into four kinds:

Kind How it works Risk
Add You put the link there yourself: a profile, a directory, a forum post. Usually low value. Low-quality directories and forum signatures with optimized links are link spam.
Ask You email site owners and ask for a link. This is outreach. Fine, if you do not pay.
Buy You pay money, products or services for a link. Link spam, unless the link is sponsored or nofollow.
Earn You make something that people link to without being asked. None. This is the goal.

The “ask” kind has well-known tactics. Resource page link building asks lists of resources to add your page. Broken link building finds a dead page with many links, offers your page as a replacement and tells the linkers. Asking to turn an unlinked brand mention into a link is another tactic, and day 06b covers it.

Earned links matter most. They are the only kind with no policy risk, and they come from people who chose to vouch for you. The best tool to earn links is often the original research from day 05. Other writers cite data that only you have.

If you find bad links to your site, you usually do nothing. Google says that “most sites will not need” its disavow tool. Use it only if the links caused a manual action, or likely will.

Digital PR

Section titled “Digital PR”

Digital PR is the practice of getting coverage and links from real publications. You pitch journalists a story, data or an expert comment. You do not ask for a link. The link comes because the journalist cites you as a source.

Ahrefs’ digital PR guide lists five common tactics:

  • Reactive PR. Journalists post requests for expert comments. You answer quickly with a useful quote.
  • Data-driven PR. You run a study or survey, then pitch the results to journalists as a story. This is the most direct use of day 05’s original research.
  • Press releases. You announce real news, such as an award or a launch.
  • Creative campaigns. A bold idea or stunt that people want to share.
  • Newsjacking. You comment on a breaking news story while it is new.

Data-driven PR works because journalists need facts that they can quote. The guide gives an example: a UK survey found that over one third of job seekers lied to get remote jobs. Hundreds of outlets picked it up. Good data stories have one clear, surprising number, a credible method and a page on your site with the full results. That page is the one that gets the links.

Influencer outreach

Section titled “Influencer outreach”

Influencer outreach is like digital PR, but it targets individual creators with their own audience, not publications. A creator reviews or mentions your product.

Two rules apply. For Google, a free product in exchange for a link is a paid link, so the link must be sponsored or nofollow. For readers, the creator must disclose the relationship. In the US, the FTC’s guide for influencers (November 2019) says that free or discounted products count as a “material connection”. The disclosure must be clear and next to the endorsement. Other countries have similar rules, so check your own.

The value of influencer outreach is mostly traffic, trust and brand mentions, not ranking credit. Day 06b explains why mentions matter even without a link.

Section titled “Outreach and link tools”

All outreach needs a list of contacts, a record of who replied and a way to follow up. Three tools in the roadmap help. Prices were checked on 13 October 2026 and change often.

Tool Main job Price (October 2026)
BuzzStream Outreach CRM: find contacts, send pitches, track replies and relationships. Starter $49 a month. Growth $174, Professional $424. Free trial.
Pitchbox Outreach automation for agencies: prospect search, templated pitches, follow-ups. Pro $300 a month ($210 a month billed yearly). Higher plans $600 and $1,200.
Majestic Backlink index and the Trust Flow and Citation Flow scores. Lite $49.99 a month. Free account with limited data.

Which do you need? For a small campaign, a spreadsheet works. Use an outreach CRM when you contact hundreds of people and need to avoid emailing the same journalist twice. Use a backlink tool, such as Majestic, Ahrefs or Semrush from day 04, to find prospects and to check the links that you get.

Key terms

Section titled “Key terms”
  • Backlink: a link from a page on another site to your site.
  • PageRank: Google’s original link analysis system, which scores a page by the number and importance of the pages that link to it.
  • Anchor text: the visible, clickable text of a link.
  • Exact-match anchor: anchor text that is the exact keyword that the target page wants to rank for.
  • rel="sponsored": a link value for ads, paid placements and affiliate links.
  • rel="ugc": a link value for links in user-generated content, such as comments.
  • rel="nofollow": a link value for links that you do not want to vouch for.
  • Hint: a signal that Google can use or ignore, not a strict rule.
  • Domain Authority (DA): Moz’s 1 to 100 score that predicts how well a whole site can rank, compared to others.
  • Page Authority (PA): Moz’s score for one page.
  • Citation Flow (CF): Majestic’s 0 to 100 score for link quantity and power.
  • Trust Flow (TF): Majestic’s 0 to 100 score for link quality, based on trusted seed sites.
  • Link building: the work of getting other sites to link to yours.
  • Outreach: contacting site owners, journalists or creators to get a link or a mention.
  • Digital PR: earning coverage and links from publications with stories, data and expert comments.
  • Data-driven PR: digital PR that pitches the results of your own research or survey.
  • Influencer outreach: getting individual creators to review, mention or link to your brand.
  • Disavow: telling Google to ignore specific links to your site.

Exercise

Section titled “Exercise”

Exercise · about 15 min

Read link attributes and a backlink profile

Part 1: see link attributes on a real site.

  1. Open https://en.wikipedia.org/wiki/PageRank in your browser.
  2. View the page source (Ctrl+U, or Cmd+Option+U on a Mac). Search for class="external.
  3. Write down the rel value on three external links. Then decide: why does Wikipedia use this value?

Part 2: read a backlink profile with free tools.

  1. Pick two sites in the same field: your own or a small one, and a well-known one.
  2. Open the free Ahrefs Website Authority Checker (https://ahrefs.com/website-authority-checker). Write down the Domain Rating of each site.
  3. Open the free Ahrefs Backlink Checker (https://ahrefs.com/backlink-checker). Check the smaller site.
  4. For ten backlinks, write down the anchor type (exact, partial, branded, naked or generic) and whether the link is nofollow.
  5. Decide: which one link would you most like to copy, and how would you try to earn it?
Show a possible solution

Part 1, checked on 13 October 2026: on the PageRank article, all 214 external links have nofollow (213 have rel="mw:ExtLink nofollow", one has rel="nofollow"). Wikipedia is user-generated content that anyone can edit. If its links passed credit, spammers would add links to it. So it marks every external link nofollow. Google’s rules would also allow ugc here, but Wikipedia uses the older value.

Part 2 depends on your sites. A typical result:

  • The well-known site has a much higher DR. This does not mean Google gives it that number. It means its link profile is much stronger in Ahrefs’ index.
  • Most anchors on the small site are branded or naked URLs. A few are generic. If many anchors are exact match, look closer: they may come from paid or made links.
  • Some backlinks are nofollow, for example from forums, comments and social profiles. That is normal.
  • The best link to copy is usually an editorial link from a relevant article, for example a news story or a blog post that cites data. To earn a similar link, find what the article cited and make a better or newer source. Then pitch it to the writer, or to writers of similar articles.

Check yourself

Section titled “Check yourself”
Two pages link to your page. Page A has 3 links in total. Page B is a directory with 300 links. Both have the same importance. In PageRank, which link helps more?
A brand sends a blogger a free blender. The blogger writes a review with a link to the brand's shop. What must the blogger do to follow Google's rules?
A client says: 'Our Domain Authority dropped from 42 to 39, so Google must have demoted us.' What is the best answer?
A site has a Citation Flow of 45 and a Trust Flow of 8. What does this most likely mean?
You have budget for one link campaign. Which plan is most likely to earn strong links with no policy risk?

Sources

Section titled “Sources”

Next

Section titled “Next”

Day 06b covers brand signals that do not need a link: entity consistency, directories and databases, social profiles, unlinked brand mentions and community presence.