
SEOmoz's biennial Search Engine Ranking Factors is finally launched. Every two years, SEOmoz survey 100 of the industry's top SEO minds. In 2009, 72 SEOs participated in the data gathering process, answering survey questions that consumed hours of time. The resulting document is an amazing aggregation of data about how search engines rank documents and, at least in my opinion, should be read by anyone serious about practicing search engine optimization.
Table of Contents
* On-Page (keyword-specific) Ranking Factors
* On-Page (non-keyword) Ranking Factors
* Page-Specific Link Popularity Ranking Factors
* Site-Wide Link-Based Ranking Factors
* Site-wide (non-link based) Ranking Factors
* Social Media/Social Graph Based Ranking Factors
* Usage Data Ranking Factors
* Negative Ranking Factors
* Factors Negatively Affecting the Value of External Links
* Geo-Targeting Factors
1-On-Page (keyword-specific) Ranking Factors
1. Keyword Use Anywhere in the Title Tag (66% very high importance).2. Keyword Use as the First Word(s) of the Title Tag (63% high importance).
3. Keyword Use in the Root Domain Name (e.g. keyword.com -60% high importance).
4. Keyword Use Anywhere in the H1 Headline Tag (49% moderate importance).
5. Keyword Use in Internal Link Anchor Text on the Page (47% moderate importance).
6. Keyword Use in External Link Anchor Text on the Page (46% moderate importance).
7. Keyword Use as the First Word(s) in the H1 Tag (45% moderate importance).
8. Keyword Use in the First 50-100 Words in HTML on the Page (45% moderate importance).
9. Keyword Use in the Subdomain Name (e.g. keyword.seomoz.org - 42% low importance).
10. Keyword Use in the Page Name URL (e.g. seomoz.org/folder/keyword.html - 38% low importance).
11. Keyword Use in the Page Folder URL (e.g. seomoz.org/keyword/page.html -37% low importance).
12. Keyword Use in other Headline Tags (35% low importance).
13. Keyword Use in Image Alt Text ( 33% minimal importance).
14. Keyword Use / Number of Repetitions in the HTML Text on the Page (33% minimal importance).
15. Keyword Use in Image Names Included on the Page (e.g. keyword.jpg - 33% minimal importance).
16. Keyword Use in or Tags (26% minimal importance).
17. Keyword Density Formula (# of Keyword Uses ÷ Total # of Terms on the Page)
(25% minimal importance).
18. Keyword Use in List Items (23% very minimal importance).
19. Keyword Use in the Page’s Query Parameters (e.g. seomoz.org/page.html?keyword)
(22% very minimal importance).
20. Keyword Use in or Tags (21% very minimal importance).
21. Keyword Use in the Meta Description Tag (19% very minimal importance).
22. Keyword Use in the Page’s File Extension (e.g. seomoz.org/page.keyword)
(12% very minimal importance).
23. Keyword Use in Comment Tags in the HTML (6% very minimal importance).
24. Keyword Use in the Meta Keywords Tag (5% very minimal importance).
Comments on On-Page (Keyword-Specific) Ranking Factors:
Andy Beal : Keyword use in external link anchor text is one of the top SEO factors overall. I’ve seen sites rank for competitive keywords—without even mentioning the keyword on-page—simply because of external link text.
Andy Beard – Keyword Use in the Meta Keywords Tag – ignore them unless using a blogging platform which can use the same keywords as tags. Google ignores them.
Christine Churchill – Taking the time to create a good title tag has the biggest payoff of any on-page criteria. Just do it!
Duncan Morris – It’s worth pointing out that even though having keywords in the meta description doesn’t impact rankings they can play a significant role in the sites click through rate from the SERPs.
Peter Wailes – Domain name keyword usage gains most of its strength through what anchor text people are then likely to link to you with, not so much from inherent value, which is lower in my opinion.



