Google Ranking Factors aka “signals”

Posted by: Marketing Guy Date posted: June 26th, 2006 Published in: Google, Search Engine Optimisation, Speculation

v7n reports that Google are using over 200 ranking factors (aka “indicators of quality”, aka “signals”) to rank websites (up from the previous figure of 100).  Big news, not a great deal of surprise, but for something to do I thought I’d see how many I can pin down.

List of Google Ranking Factors (in no particular order)

Yeh some of this stuff is pure speculation so don’t piss and moan.  Just wanted to fire everything down and see what I ended up with.  All these items may or may not have an impact (be it positive or negative) on the ranking of the page.

  • Page Title tag (length, keyword use, keyword positioning)
  • H1
  • H2
  • H3
  • H4
  • H5
  • H6 (yeh all 6 are listed as they are likely to be given different weights)
  • Meta description
  • Meta keywords
  • Overall page keyword density
  • First paragraph keyword density
  • Last paragraph keyword density
  • Synonym keyword density / use
  • Bold tag
  • Underline tag
  • Em tag
  • Strong tag
  • Itallic tag
  • Could probably add more, but lets cap it by saying different forms of HTML markup may carry different weights
  • Use of markup (generally) to improve accessibility and usability of the page – that is, a page with a lot of text may pull more value from H1, H2, H3 headings than a page with only 100 words.
  • Link text used (to internal pages)
  • Link text used (to external pages)
  • Quantity of links on page (any type)
  • External sites deep linking to the page
  • The link text used by external pages linking to the page
  • The link text used by internal pages linking to the page
  • The text surrounding internal links to the page
  • The text surrounding external links to the page
  • Location (on page) of internal links to the page
  • Location (on page) of external links to the page
  • The source and relative authoritative status of external links to the page / root domain.
  • ALT text
  • Keywords in domain name
  • Keywords in directory structure
  • Keywords in subdomain
  • The PageRank of the page
  • The PageRank of the site’s homepage
  • The PageRank of internal pages linking to the page
  • The PageRank of external pages linking to the page
  • The overall theme of the site (ie, niche or broad)
  • Average word count per page compared to industry averages
  • The general competitiveness of the industry
  • The theme of internal linking pages (based on how related they are to the target page)
  • The theme of external linking pages (based on how related they are to the target page)
  • The TLD of your domain
  • The TLD of external linking pages
  • The IP address of the site’s host (relevant to local targeting)
  • The IP address of external linking pages
  • The age of the domain name
  • The age of the domain name relative to the amount of time the current owner has controlled it
  • The age of the domain name of external linking sites
  • The age of the domain name of sites you link to (train of thought – linking to only sites that are new doesn’t seem “natural” – you are more likely to link to established sites)
  • The frequency that the content on your page is updated – perhaps not a factor for all industries, but relevant to some (eg news sites)
  • The frequency that the overall content on the domain is updated - new content posting frequency could be an indicator of the type of site (and as such, relevance to certain searches)
  • The frequency that your site gains new links over time (link growth)
  • Link growth compared to industry averages
  • Content growth compared to industry averages
  • Sources of links compared to industry averages
  • General sources of links (ie, if 90% of your links are from free directories, this could be used to “judge” your site)
  • External link text compared to industry norms (how many plain URL links, how many target keyword links, how many generic word links, etc vs what’s usual for the industry)
  • CTR of organic SERPs
  • Time spent on site after CTR from organic SERPs (monitored via toolbar or clicking back on browser and hitting a new listing)
  • Relevance based on search actions (will a user click to your site, then leave to refine their search further?)
  • Authoritative status (just as sites could be “flagged” as potential spam and as such devalued, others could be flagged as authoritative and given a bit more slack or a boost).
  • SEO flagged?  Many sites are clearly made by SEOs (common use of keywords in key areas such as inbound links, title tags, etc) – this could be a signal of quality.
  • DMOZ listing – either a) DMOZ considered (independently) authoritative or b) receives authoritative flag by virtue of Google’s system of defining authoritative sites.
  • Accessibility of the page
  • Duplication of content on the site
  • Uniqueness of the content of the page / site (keyword ladden content and “perfect SEO” pages could be considered to be partially duplicated content)
  • Language of the page / site
  • Words focused on the purpose of the site.  For example, ecommerce sites using the words “buy”, “sell”, “for sale”, “to buy” may rank better for related queries as the user intention is matched with the focus of the site.  Although this could simply be coincidental to using the keywords as normal (keyword density, etc)
  • Historical rankings of the site – a site which consistently ranks well should continue to do so.  A new site that begins to rank well may raise flags
  • Google sitemaps – may influence speed of indexing and therefore an indirect factor in the ability to rank on Google – most likely not a direct factor in ranking
  • Type of site – I recently hypothesised that Google treat different types of sites (eg blogs) differently.
  • Industry – already mentioned in other aspects, but worth generalising – Google most likely treat sites in different industries in different ways.  Broad generalisation – PPC (porn, pills, casinos) are likely to require higher levels of authorative IBLs for example, before ranking well compared to other industries.
  • Size of the site (how many pages) compared to industry average
  • Google spam reporting – perhaps an indirect factor, but could ultimately impact ranking – if an industry receives a large amount of spam reports, this could affect how Google approach rankings (see point 75)
  • Use of off the shelve software – WordPress, PhPbb, vBulletin, etc are all easily identified.  Some off the shelve software is more prone to spam than others
  • History with Google – whois data, Adsense, Adwords, sitemaps, etc data can easily be collated and used to judge overall quality.  Ie, Authoritative publishers?
  • Use of nofollow attribute (generally)
  • Use of nofollow attribute compared to other OBLs.
  • Quality of sites linked to (quantity of spam sites compared to quantity of quality sites)
  • Number of links to Google you have ;)
  • Age of links to your page
  • Number of other external links on external pages that link to you
  • Link relationship with other sites in your industry
  • Link relationship with other sites on your IP range
  • Link relationship with other sites in general
  • Link relationship with academic, government and news sites
  • Affiliate links
  • Uptime of your site
  • URL length and use of keywords (rehashed from a previous point)
  • Broken external links on your page