Rand Fishkin, Wizard of Moz
| @randfish | rand@moz.com Search Ranking Factors 2015 What data, opinions, and testing have revealed about how Google’s rankings operate.

Slides Online at:
Bit.ly/rankslides2015

A look at Google’s algorithm
in 2015 according to 150 professional SEOs

We usedto show graphics like
this to illustratethe relativeimportanceof differentareasof optimizationto Google’s algorithm. 2013

But a pie chart suggests
that you can only get so much value from any given set of features. In reality, factors like higher link authority on your domain have as almost unlimited ability to positively influence rankings

Thus, we’vegot a new wayto
illustrate how rankingfactors fit together:

Most interestingto me is what’s
happenedto SEO professionals’opinionsover time…

2009 2011 2013

2015 (in blasphemous pie chart
form to illustrate comparative change)

2009 2011
2013 2015

Afew of the opinions about
factors in particular stand out:

Page-LevelLink Features Domain-LevelLink Features Page-LevelKeywordFeatures
2009 2011 2013 2015 43% 22% 19.15% 14.54% 2009 2011 2013 2015 24% 21% 20.94% 14.60% 2009 2011 2013 2015 15% 14% 14.94% 13.97%

1) Professional SEOs feel that,
on average, the algo is flattening, and the days of a single factor having an overwhelming impact are fading. Takeaways:

2)After years of dominating the
algo, links, while still powerful, don’t feel like an overwhelming ranking force to SEOs. Takeaways:

3) Engagement data is on
the rise. If growth rate continues, by our next survey, it may be in the top two features. Takeaways:

Correlation doesn’t imply causation… so
why are we still talking about it in SEO?!

Becausecorrelationtells us somethingelse of great
value: Correlation DOESN’T tell us why one page ranks higher than another. It DOES tell us what features higher- ranking pages tend to have over their lower ranking peers.

Do correlationcoefficients in the 0.1
– 0.4 range (typical for single factors in searchengine studies) mean anything? Debunk statements about what’s NOT causal in rankings 3 UsefulApplications: Show relative potential influence ID factors for more testing / investigation

Debunkingmyths with correlationdata is easy:
Google are losers! The more ads you buy, the higher they rank you.

Debunkingmyths with correlationdata is easy:
A negative correlation of -0.03 disproves the idea that more ad slots = higher rankings.

Coefficients canalso be used to
show relativecorrelation: The best SEOs use multiple repetitions of keywords in their titles. I guarantee it works better than some fancy LDA model.

On average, content that better
fits an LDA topic model dramatically outperforms KW repetition in the title Coefficients canalso be used to show relativecorrelation:

Correlationnumberscan leadus to interestingtheoriesthat we
can then validatethrough other means: Could it be that partial match anchor text now has equal or greater ranking influence than exact match?

Correlationnumberscan leadus to interestingtheoriesthat we
can then validatethrough other means: Let’s go run some experiments to see if this is true y’all!

NOTE: Inanalgorithmwith100s–1000sofrankinginputs,we shouldn’texpectanysingleelementtohave thekindsofhigh correlationsseeninlesscomplexinputscenarios.
Single factors correlate with higher Google rankings in this range.

How do various web metrics
correlate with higher Google rankings in 2015?

In May 2015, Moz collected
16,521 unique SERPs from Google.com (US). Full methodology here

Look Familiar? Link metrics’ correlations
w/ rankings have been similar for ~6 years

Moz & Ahrefs For the
first time, we compared Mozscape’s link correlations against Ahrefs… And found nearly identical results for both.

Social Shares Correlations are down
~10-15% from their high in 2013.

Traffic & Engagement For the
first time, we measured usage data. While traffic looks strongly correlated, engagement metrics have weaker numbers. Trafficandengagement metricsvia

Keyword Use & On-Page Optimization
As we get more sophisticated in our text-modeling abilities, we’re seeing higher correlations (though still low relative to links & social shares)

For the first time, we
also broke correlationsdownby categoryof keywords/SERPs

Health websites that link out
more tend to rank higher. Dining sites see almost no correlation between linking out & ranking.

It tended be more present
in higher ranking sites for these verticals Anchor text had a smaller relationship w/ high rankings in these verticals

Those meager restaurant websites? Looks
like Google doesn’t mind much. Buzzfeed & Upworthy are always showing how lengthier articles perform better for them.

Twitter & Facebook have very
similar relative correlations, which fits w/ Google’s statements that they don’t directly use either. In some verticals, social sharing is much less connected to ranking positions than others

1) Correlations with links have
remained relatively similar, suggesting that perhaps links haven’t faded in influence as much as some in our industry have suggested. Takeaways:

2) We need more sophisticated
on-page analysis tools. With the right algorithms/ software, we may find real opportunities to improve rankings through content. Takeaways:

3) Correlation is even more
useful (and interesting) on subsets of SERPs than on an entire corpus. In the future, calculating correlations for the SERPs you/your company care about may become standard. Takeaways:

3 Examples of What Correlation
& Experimentation Can Do: #1: Help us validate what Google says #2: Verify theories about what’s in Google’s algo #3: Lead us to better tactical approaches

Validating Some of Google’s Statements
On Secure Sites

ViaGoogleWebmasterCentralBlog

ViaRand’sGoogle+

HTTPS URLs have a 0.04
correlation w/ higher rankings… much lower than many features Google says don’t impact rankings.

Here’s another example of a
potentially misleading statement, and we’ll be working to verify it, too: ViaSERoundtable

Investigating SEOs’ Longstanding Theories re:
Raw URL Mentions

Using data from Fresh Web
Explorer, we can see how many mentions aURLreceives in a given day/week/month

The correlations w/ URL mentions
are pretty high – in the range of social shares and links (0.19 for full domain, 0.17 for root domain)

ViaStoneTempleBlog(andIMECLabs) So, the crew at
IMEC Labs ran a test!

Results suggest raw URL mentions
had no impact on rankings, certainly nothing like the impact of links.

A Look at Links &
Social Shares in Google’s Rankings

We knowthat linkscan still overwhelm
otherranking signals. Via RishiLakhanionRefugeeks Pointing a few anchor-text links at this blocked-by-robots page on Matt’s blog made it rank (even in 2015).

We knowaboutloadsof linkelementsthat influencerank-boosting ability:
1) Anchor Text 2) PageRank 3) Relevance 4) Domain Authority 5) Location on the Page 6) Internal vs. External 7) Quality of Other Links on Page/Site 8) Editorial Weight 9) Engagement w/ Linking & Linked Pages 10) Follow vs. Nofollow

11) Source Depth 12) Text
vs. Img 13) Link Age 14) Topical Authority of Source 16) Spam Signals 17) Speed/Acceleration of New Link Sources 18) Author Authority 19) 1st Link to Target on Page vs Duplicate Links 10) Prior Links to Target from Source Domain15) Javascript vs. HTML We knowaboutloadsof linkelementsthat influencerank-boosting ability:

This stuff mattered a lot
whenwe did manuallink buildingto move rankings But today,many of us justlet content buildlinksfor us, right?

Moz & Buzzfeed joined forces
for a report looking at 1 million pieces of content. DataviaBuzzsumo&Moz’sJointStudy

Content+ SocialSharing= Links? DataviaBuzzsumo&Moz’sJointStudy Median
# of links across a million pieces of content in Buzzsumo’s database?.... 1 linking root domain.

This is a powerlaw distribution–
the top contentgetsthe overwhelmingmajority of linksand shares.

The reality of social amplification
and earning links is… 0.028? That’s too close to 0 to infer any consistent, direct influence.

For the most heavily shared
content, there’s a little bit more of a correlation, but it’s small enough that relying on social shares to earn your links is probably folly. We tried segmenting the samples:

This data showswhy I can’tendorseeitherof
these common maxims in SEO/contentmarketing: Create good, unique content and Google will figure out the rest. The best way to earn links is to create great content.

In the past,I presenteda conceptthat,basedon
this data, now appearsto be fundamentallyflawed:

Publish Amplify Grow network Rank
for slightly more competitive terms & phrases Get links Grow authority Earn search traffic

Publish Amplify Grow network Rank
for slightly more competitive terms & phrases Get links Grow authority Earn search traffic This doesn’t just happen. Link building – outreach, embeds, nudges, etc – are still essential.

1) Social shares by themselves
almost never lead directly to the quantities of links necessary to rank well. Takeaways:

2) Content that performs extraordinarily
well on social networks and ranks well in search engines may not be benefitting solely from links. Takeaways:

bit.ly/rankingfactors2015
Allthedatafromtherankingfactors
reportcanbefoundat:

Rand Fishkin, Wizard of Moz
| @randfish | rand@moz.com Bit.ly/rankslides2015