Module 6: PageRank & Links
Classic 6 Patents 1.5 hoursFrom the original PageRank to the Reasonable Surfer model - how link value has evolved.
Patents Covered
| # | Patent | Year | Key Innovation |
|---|---|---|---|
| 44 | US 6,285,999B1 | 1998 | Original PageRank |
| 45 | US 8,117,209B1 | 2012 | Reasonable Surfer Model |
| 46 | US 9165040B1 | - | Link Graph Distance |
| 47 | US 7,565,358B2 | - | Agent Rank (Author) |
| 48 | US 9,558,233B1 | - | Traffic-Based Quality |
| 49 | US 7,716,225B1 | - | Behavior-Based Ranking |
Patent 44: Original PageRank
Patent: US 6,285,999B1Inventor: Lawrence Page The algorithm that started it all
The Core Concept
PageRank treats links as votes. A page with more links from important pages is more important.
The Original Formula
PR(A) = (1-d) + d * (PR(T1)/C(T1) + PR(T2)/C(T2) + ... + PR(Tn)/C(Tn))Where:
- PR(A) = PageRank of page A
- d = damping factor (typically 0.85)
- PR(Ti) = PageRank of page Ti that links to A
- C(Ti) = number of outbound links from Ti
Key Insights
- Not all links are equal - Links from high-PR pages pass more value
- Links are divided - More outbound links = less value per link
- Damping factor - Simulates random surfing behavior
Patent 45: Reasonable Surfer Model
Patent: US 8,117,209B1 / US 7,716,225THE EVOLUTION THAT CHANGED LINK BUILDING
Beyond Simple Vote Counting
The Reasonable Surfer model recognizes that not all links are equally likely to be clicked.
Link Value Factors
| Factor | Higher Value | Lower Value |
|---|---|---|
| Position | Main content, above fold | Footer, sidebar |
| Context | Editorial mention | Blogroll, template |
| Anchor text | Descriptive, relevant | "Click here", URL |
| Font/Style | Normal text, prominent | Small, de-emphasized |
| Surrounding text | Relevant sentences | No context |
Practical Implications
High-Value Link Characteristics
- In main content area
- Editorially placed
- Surrounded by relevant text
- Descriptive anchor text
- Prominent placement
Low-Value Link Characteristics
- Footer or sidebar
- Template/sitewide
- No surrounding context
- Generic anchor text
- Small or styled differently
Patent 47: Agent Rank
Patent: US 7,565,358B2Author authority affects content ranking
The Author Entity Concept
How Author Authority Works
- Author is recognized as an entity
- Content by author is tracked
- Quality signals aggregate to author
- Future content benefits from author reputation
Building Author Authority
| Action | Impact |
|---|---|
| Consistent byline across sites | Entity recognition |
| Links to author profiles | Entity connection |
| Quality content history | Authority building |
| Expert credentials | Trust signals |
| Social validation | Entity verification |
Patent 48: Traffic-Based Link Quality
Patent: US 9,558,233B1Links that generate actual traffic are more valuable
The Shift from Theory to Reality
What This Means
Google can see:
- Whether links actually get clicked
- How much traffic flows through links
- User behavior after clicking
SEO Implication
Critical Insight
Links that nobody clicks are worth less than links that drive actual traffic. Build links people will actually use.
Modern Link Building Strategy
Tier 1: Editorial Links (Highest Value)
Characteristics:
- Main content placement
- Relevant anchor text
- Surrounding context
- Likely to generate clicks
Tier 2: Resource Links (Good Value)
Examples:
- Resource pages
- Tool directories
- Industry roundups
- Expert compilations
Tier 3: Profile/Directory Links (Lower Value)
Examples:
- Business directories
- Social profiles
- Association listings
- Author bios
What to Avoid
Low/Negative Value
- Footer links (template)
- Sitewide links (suspicious pattern)
- Irrelevant anchor text
- No surrounding context
- Clearly purchased
- PBN networks
Link Quality Assessment
For Incoming Links
| Signal | Good | Bad |
|---|---|---|
| Placement | Main content | Footer/sidebar |
| Context | Relevant paragraph | No context |
| Anchor | Descriptive | Exact match spam |
| Source authority | Established site | New/thin site |
| Traffic potential | Likely clicks | No clicks |
For Link Building Targets
Implementation Checklist
Link Audit
- [ ] Identify high-value incoming links
- [ ] Find low-value/risky links
- [ ] Check anchor text distribution
- [ ] Analyze link placement patterns
Link Building
- [ ] Focus on editorial opportunities
- [ ] Create linkable assets
- [ ] Build author authority
- [ ] Target relevant, high-traffic sites
- [ ] Ensure links will be clicked
Internal Linking
- [ ] Main content links (not just navigation)
- [ ] Relevant anchor text
- [ ] Strategic link flow to important pages
- [ ] Avoid over-optimization patterns
Module Quiz
Question 1: What does the Reasonable Surfer model consider that original PageRank didn't?
Answer: The Reasonable Surfer model considers the probability that a link will actually be clicked, based on position, anchor text, font size, surrounding context, and whether it's editorial or template-based.
Question 2: Why are footer links worth less than main content links?
Answer: Footer links are template-based (appear on every page), unlikely to be clicked, lack surrounding context, and don't represent editorial endorsement. The Reasonable Surfer model assigns them lower click probability.
Question 3: How does traffic-based quality affect link value?
Answer: Links that generate actual clicks and traffic are more valuable than links that exist but are never clicked. Google can measure real traffic flow and values links that users actually use.
Key Takeaways
- Position matters - Main content links beat footer/sidebar
- Context is crucial - Editorial mentions beat template links
- Traffic validates links - Clicked links are worth more
- Author authority exists - Build personal brand, not just site brand
Next Steps
Continue to Module 7: User Behavior Signals →
Learn how clicks, engagement, and user signals affect rankings.