This article describes different facets of the onsite and offsite factors Google uses to rank pages in the serps. It is really important to follow search engine ranking factors.
Google Onsite Search Engine Ranking Factors
Age of Site
“Refers to the date when the site has gone live and seen by the search engines (note that this can change if a domain switches ownership) – Importance 4.9%”
The site age is one of the single most important criteria of the Google algorithm, especially for new sites in competitive niches. This effect is created by algorithm components rather than an algorithm component itself. This factor become increasingly more important in the future.
Historical Performance of Site
“Algorithm based on CTR, bounce rate, time spent on page/site, social bookmarks, etc. that Google collect through use of their sites, toolbar, free wifi, Google analytics, etc. (note that Google has never publicly admitted to use this data) -Importance 4.6%”
There’s little doubt that the search engines see what users are doing, especially users that have opted-in to certain search engine products. I believe Google is still at the learning stage here. Gathering data and try to understand it. This factor is going to become important in the future.
Link Popularity within the Sites Internal Link Structure
” Refers to the importance of internal links pointing to the target page – Importance 4.2%”
There are multiple examples of top rankings for competitive keywords with only internal links pointed to it. Try to use anchor text links with keywords in the site menus and within the content when applicable.
TLD Extension of Site
“Refers to the top-level domain extension of the site (edu, gov, us, ca, com, etc) – Importance 2.8%”
More a important factor for country specific than for edu, gov, com, net, and org sites.
HTML Validation of Document
” Validation of HTML page code as per the W3C consortium, an authoritative body on the standards of web-compatible code – importance 1.2%”
Good content have noting to do with HTML Validation from pages. This is and shall probably never be a ranking factor, like it should be. But the chance is that a part of the text disappears for the spiders when a tag is not closed properly.
Google Offsite Search Engine Ranking Factors
Anchor Text of Inbound Link
“Refers to the importance of text used in the anchor tag of inbound links – Importance 4.7%”
Anchor text of inbound links is for some years an important criterion of the Google algorithm. How a link to a page is a vote for that page, so is the anchor text a vote for a keyword for that page. This is the main reason why you can find Wikipedia on the top of many searches for competitive keywords in Google.
Importance of PageRank
“Refers to the importance of link popularity (pagerank) of the target page – Importance 3.2 %”
The importance of pagerank has been downgraded dramatically. There are many examples of low pagerank pages outranking high pagerank pages for competitive keywords. Now to day is the keywords used in the anchor tag from links pointing to the target page more important than the links to the target page on its own. Remember that the pagerank that Google display in the toolbar is outdated and toolbar pagerank updates occurring at three-month intervals.
Topical Relevance of Inbound Links
“The subject-specific relationship between the sites linking to the target page – Importance 1.9%”
There are multiple examples of pages with top rankings who have inbound links from unrelated sites. But topical relevance can become increasingly more important in the future. However links from topic related sites result has a higher CTR than unrelated sites. More important is the keywords used in the anchor tag from links pointing to the page.