Search Engine Ranking Factors

The most important factors for search engine rankings as determined by the world's top SEO Experts.

The search engines use hundreds of different factors to rank the different websites when someone conducts a search. Some factors are declared by the search engines themselves but most are unknown. The best resource we have for determining the most important ranking factors is SEOmoz's Biennial Ranking Factors survey. Basically they survey the world's top SEO experts and determine the consensus on which factors are most important for determining a website's search engine ranking.

These are the top five ranking factors determined in the last survey (2009):

1. Keyword Focused Anchor Text from External Links
2. External Link Popularity (quantity/quality of external links)
3. Diversity of Link Sources (links from many unique root domains)
4. Keyword Use Anywhere in the Title Tag
5. Trustworthiness of the Domain Based on Link Distance from Trusted Domains (e.g. TrustRank, Domain mozTrust, etc.)

Four of the top five factors are related to incoming links. That's why link building is such an important part of Search Engine Optimisation. If we focus on the other half of SEO, Onsite SEO, the most important ranking factors are:

1. Keyword Use Anywhere in the Title Tag
2. Existence of Substantive, Unique Content on the Page
3. Keyword Use as the First Word(s) of the Title Tag
4. Keyword Use in the Root Domain Name (e.g. keyword.com)
5. Site Architecture of the Domain (whether intelligent, useful hierarchies are employed)

The survey is due to be redone this year, around August. Which factors do you think will have changed? Will there be any new factors that we haven't seen before?