Recently, SEOmoz released a fantastic biennial search engine rankings report. Every two years, SEOmoz interviews the top 100 minds in the SEO industry. This time, they have gathered data from the top 72 SEO professionals to give a clear idea of how the search engines rank documents.
This aggregate data gives any SEO professional the key factors that Google uses when it comes to ranking sites on the SERPs. It is a thoroughly interesting read and will assist all SEO professionals be it a beginner or an advanced level practitioner.
The report is split into five sections namely The Overview, Ranking Factors, Link Building, Additional SEO Data and Contributors. We will consider the three top ranking factors, top three negative ranking and top three contentious factors under each of above sections.
I am listing only the importance figures and not the consensus figures. I am also writing only about the Overview and Ranking factors. I will reserve the rest of the sections for a later post.
Overview of Search Engine Ranking Factors
Top 3 Ranking Factors
1)Keyword Focused Anchor Text from External Links: 73% very high importance
This is the text in clickable links that are pointing to your site from external sources. It reinforces the confirmation of your page content to Google if the anchor text is appropriate and matches your internal anchor text on your site.
2)External Link Popularity: 71% very high importance
This refers to the quality/quantity of external links
3) Diversity of Link Sources: 67% very high importance
This is the number of links from several diverse root domains
Top 3 Negative Ranking Factors
1)Cloaking with Malicious/Manipulative Intent: 68% very high importance
If a site shows different content on the same page to humans and search engine bots, then it is cloaking in its basic form.
This is done by looking at the user agent. If the user agent is a bot, then a certain page is shown. If the user agent is a human, then a different version of the page is shown. If the intent is one of malice, then it is deception at its worst to fool the search engines.
2)Link Acquisition from Link Brokers/Sellers: 56% high importance
Since link acquisition has assumed gargantuan proportions with Pagerank adding fuel to fire, the notion of gaining inbound links at any cost is acknowledged by Google. There are numerous link brokers in the market today peddling links to anyone for a tidy sum. Google has been penalising paid links and advises that a nofollow be applied to such links. Else a message saying it is a paid link should be displayed to avoid a penalty.
3)Links From The Page to Webspam Sites: 51% moderate importance
Google definitely looks at the percentage of inbound links and outbound links to spam sites from a given page/site. If the proportion of links to spammy sites is quite high than the average benchmark (any good quality site is bound to gain inbound spammy links over time and Google factors this into its algorithms), then a penalty is there in the asking.
Top 3 Most Contentious Factors
1)Cloaking by Cookie Detection: 16.3% strong contention
3)Hiding Text with same/similar colored text/background: 15.3% moderate contention
A previous post of mine titled Serving Content Based on IP Address & Cookies  answers the top two contentious factors.
Search Engine Ranking Factors
On page (Keyword Specific) Ranking Factors
1)Keyword Used Anywhere In The Title Tag: 66% very high importance
This can lead to a tussle between the keyword and the company brand. If a brand is popular, it is then a good idea to put the brand ahead of the keyword.
2) Keyword Used as the First Word(s) of the Title Tag: 63% high importance
This really depends on the branding priorities for a business in question. If the site is owned by an affiliate marketer, then it is prudent to have the title starting off with the keyword.
3)Keyword Use in the Root Domain Name (e.g. keyword.com) 60% high importance
This is very useful in the event of external sites linking to a site using just the URL of the linked to site. The keyword present in the domain name enhances the keyword value in the anchor text.
On page (Non Keyword Specific) Ranking Factors
1)Unique Content on the Page: 65% very high importance
There is no doubt that the quality of content on a site plays a distinct part in being identified as unique by Google and is vital to the site getting ranked at the top of the SERPs for its niche.
2) Freshness of Content: 50% moderate importance
Regularly updated content keeps the bots paying regular visits to a site. The QDF (Query Deserves Freshness) component in Google’s algorithm helps a new site with fresh content rank ahead of the well established sites for a limited period of time before it settles down on page 3 or beyond. This gives new sites much needed exposure though for a limited time.
3) Use of Links on the Page that Point to Other URLs on this Domain: 41% low importance
The internal linking architecture of a site is vital to help search engines understand the more important and not so important pages. The use of appropriate anchor text also helps the bots analyse the reputation aspect of linking where the anchor text pointing to a page is really representative of the content on the page it points to.
Page-Specific Link Popularity Ranking Factors
1)Keyword-Focused Anchor Text from External Links: 73% very high importance
It is not always possible to have lot of control over the anchor text coming from external sources. Anything that is close to the perfect anchor text is an asset. Good quality content on a site is a huge asset in that it has a higher chance of getting linked to using appropriate anchor text.
2)External Link Popularity (quantity/quality of external links): 71% very high importance
The inbound links from well trusted authoritative sites are of high quality and certainly play a good part in the successful ranking of a site on the SERPs.
3)Diversity of Link Sources :67% very high importance
This refers to links from a diverse set of root domains to a site.
Sitewide Link Based Ranking Factors
1)Trustworthiness of the Domain Based on Link Hops from Trusted Domains: 66% Very High Importance
If your site is linked to a trustworthy domain (seed domain) in as few hops as possible, your site is bound to gain in domain trust and integrity in the eyes of search engines.
2)Global Link Popularity of the Domain: 64% High Importance
This centers around iterative link popularity of a domain like PageRank measure. The number of inbound and outbound links for a domain in the entire web link graph reflects this measure.
3)Link Diversity of the Domain: 64% High Importance
This refers to the number of links from diverse root domains linking to pages on a domain.
Sitewide Non Link Based Ranking Factors
1)Site Architecture of the Domain: 52% Moderate Importance
An intelligent site architecture is a good way to reveal to the search engines which pages are important and the ones that are not so important. Ideally, spiders must be able to find the money pages within three clicks of the home page. I remember reading this statement – If content is king on the web, then the site architecture is his palace.
2)External Links to Reputed Trustworthy Sites/Pages: 37% low importance
It is important to maintain a good neighbourhood and that is determined by a site’s linking to good quality reputed sites with good domain trust.
3)Length of Domain Registration: 37% low importance
A domain that has existed for a long time and has not changed ownership is a mature domain and it carries a lot of weight. Google tends to favour content from such sites ahead of younger domains that have quality content. Moreover, if a domain is registered for a lengthy period of time, it could be an indicator to Google that the domain is going to be in for the long haul.
Social Media/Social Graph Based Ranking Factors
1)Delicious Data About the Domain or Page: 21% Very Minimal Importance
Delicious is a popular bookmarking service. There is no doubt that when a site gets bookmarked by a lot of users, it is certainly popular. Most of these links are nofollows. It is highly unlikely that these can influence search engine ranking algorithms.
2)StumbleUpon Data About the Domain or Page: 19% very minimal importance
3)Twitter Data About the Domain or Page: 17% very minimal importance
It is a fact that Twitter plays a huge part in the cannibalisation of the web link graph (as Rand uses it) with shortened URLs and hordes of users twittering these links back and forth. From my personal experience, I find that a tweet on content I publish really helps in getting spidered by the bots rapidly as the bots keep monitoring the Twitter landscape. It is a matter of great interest and remains to be seen if Twitter can directly influence search engine rankings in future.
Usage Data Ranking Factors
1)Historical Click-Through Rate from Search Results to the Exact Page/URL: 42% low importance
2)Historical Click-Through Rate from Search Results to Pages on this Domain: 39% low importance
3)Search Queries for the Domain Name or Associated Brand: 36% low importance
Though these are user based heuristics, it may not count for much in terms of impacting the rankings at this point of time. But the Google toolbar collects this information and can introduce them into its algorithms at any point of time (if it has not done so already).
The only problem is the qualitative aspect of data collected. If a user searches for something and finds what she is looking for on the page she lands on by clicking on the first result on the SERPs, then she hits the back button and goes on to search something else. The content is extremely relevant to what the user searched for though Analytics can show it as one with a high bounce rate. It will be hard to measure these finer aspects.
Negative Ranking Factors
1)Cloaking with Malicious/Manipulative Intent: 68% very high importance
This is definitely a no go zone when it comes to deceptive SEO. It is a surefire way to get a site banned from the search engines.
2)Link Acquisition from Known Link Brokers/Sellers: 56% high importance
Google penalises link trading very heavily. It would be advisable to use either a nofollow or clearly mention that it is a paid link. ALternatively, block the page pointed to by the paid link using robots.txt file.
3)Links from the Page to Web Spam Sites/Pages: 51% moderate importance
Factors Negatively Affecting the Value of an External Link
1)Domain Banned from Google’s Index for Web Spam: 70% very high importance
2)Domain’s Rankings Penalized in Google for Web Spam: 65% very high importance
3)Link is Determined to be “Paid” Rather than Editorially Given: 63% high importance
These factors have cropped up previously in this post. So it is a clear reminder to stay away from such practices.
1)Country Code TLD of the Root Domain (e.g. .co.uk, .de, .fr, .com.au, etc.): 69% very high importance
2)Language of the Content Used on the Site: 63% high importance
3)Links from Other Domains Targeted to the Country/Region: 60% high importance
A domain extension matching the country in which the site does business in is a good heuristic to give Google an idea of the geo location. It would be ideal if the site is hosted in that particular country it is targeting.
Google can be given a better idea if the site administrartor can set the geo-targeting preference in the Webmasters Central console.
The language of the content used on the site is a good indicator. In saying this, Google itself has admitted that its IP based geotargeting is not accurate in a multilingual country like Switzerland where a German content site can be served to French speaking person. In such situations, it would be wise to give links to the various languages in which content is available and allow the user to make the appropriate language selection.
If the site is targeting Australia, then inbound links from other .com.au sites will be extremely beneficial and help Google rank the site more accurately in the country specific rankings.
I have highlighted these factors in a post titled Serving Content Based on IP Address and Cookies 
For a thorough read of the original exhaustive report, visit SEOmoz and read through the post titled SEOmoz’s Biennial Ranking Factors 2009 Released