This document discusses the role of links in SEO. It covers internal vs external links, PageRank, domain authority and page authority, dofollow vs nofollow links, types of traffic, what SEO and link building are, negative SEO and the disavow tool. Key points include how links pass "link juice" to increase page weights, the importance of having a diversified backlink profile from relevant sites for rankings, and how unnatural or fake links can hurt a site's performance.

1. The Role Of Links In SEO
Jérôme Verstrynge
For Ligatures.net
December, 2014
License: CC BY-ND 4.0

2. Table Of Contents
●
Internal vs External
●
PageRank
●
Domain & Page
Authority
●
DOFOLLOW &
NOFOLLOW
●
Types of Traffic
●
SEO & Link Building
●
Negative SEO
●
Disavow Tool
●
Facts &
Recommendations

3. Links: Internal vs External
●
Websites are identified by their domain name (site1.com, site2.com...)
●
Links: means to reference and to navigate between web pages
●
Internal link: between same site pages (page A to B)
●
External link: between different site pages (page B to C)
●
Backlink: from another site to your site (site2.com has a site1.com backlink)
Page
A
Page
B
Page
C
http://site1.com
http://site2.com

4. Understanding PageRank
●
Google attributes a weight to all
web pages
●
This weight is divided by the
number of outbound links
●
This amount (also called linked
juice) is added to weight of target
pages
●
The process is repeated infinitely,
as links are created and removed
between pages on the Internet
●
PageRank (PR): a 0 to 10 value
attributed to each page, which is a
logarithmic function of its weight
2.5
10
2.5 2.52.5
Today, Google
does not publish
PageRank
information anymore!

5. Domain Authority & Page Authority
●
Yesterday
– High PageRank meant high
ranking in search results
– People started creating
unnatural (i.e. fake)
backlinks
●
Today
– Search engines:
●
Can I trust a backlink?
●
Are the source and target
pages/websites related?
●
What about content?
– Backlinks are necessary to
rank high, but not sufficient
●
Moz
– Created domain authority
(DA) & page authority (PA)
– Metric based on many
factors (0-100 logarithmic
scale)
– Indicates likeliness to rank
at Google
– DA & PA are publish
frequently, replacing PR

6. Do Follow & No Follow
●
DOFOLLOW &
NOFOLLOW: attributes
set on links (or whole web
pages)
●
A kind of endorsement
●
Tells search engine web
crawlers to navigate
through or not
●
Also enables the passing
of link juice or not
2.5
10
- 2.5-
NOFOLLOW
Users see no
difference between
DOFOLLOW and
NOFOLLOW links

7. Types Of Traffic
●
Organic traffic: user clicking on links displayed in
search engine results (excluding advertising links)
●
Direct traffic: users typing URLs in their browser,
clicking links in their favorites, emails, documents
●
Referral traffic: users clicking on links located on
external website
●
Paid traffic: any traffic coming from sponsored links or
web page advertising
●
Social traffic: direct traffic coming from social websites

8. What is SEO? What Is Link Building?
●
SEO: Search Engine Optimization (techniques for ranking)
●
Link Building: a SEO method aiming at increasing organic
traffic by increasing the number of backlinks to a website
●
Link Scheme: a set of unnatural links organized between
one or more sites to help target websites rank higher
– Some malicious people use link schemes to improve rankings
– ...but negative return on investment on the long term (always)!
– Unnatural links networks are detected better and better
– Unnatural links impact rankings negatively
– Can trigger severe ranking penalties too

9. What Is Negative SEO?
●
Ranking has become hard:
– High competition in many niches
– Less return from link building
●
“If I can't rank higher, I can hurt ranking of
competition”
●
Negative SEO: unnatural links pointing at
competition, created by malicious people
●
Solution? The disavow tool

10. What is the Disavow Tool? Link Profile?
●
A Google tool to neutralize
backlinks to your web site
– A kind of reverse
NOFOLLOW feature
– Protects from unnatural
links negativity
– Operates at the link level or
website level
●
Link profile: the set of
backlinks of a website
-
10
2.5 2.52.5
Disavowed links are
effective after they
are reprocessed by
web crawlers and a
refresh at Google has
happened
DISAVOWED

11. Facts & Recommendations
●
A bad internal link structure hurts your SEO
●
PageRank is not king in computing rankings anymore
●
Don't make a religion of Domain & Page Authority
●
Content is as necessary as backlinks to rank
●
NOFOLLOW links have value, they bring traffic
●
Successful websites have a diversified backlink profile
●
Focus on diverse sources of traffic

12. Further Readings
●
Getting started with SEO
●
SEO guidelines & checklists
Click