SeoBook thinks that search engines use ClickStream Analysis to decide what pages are relevent for the search results.   I don’t think it’s practical for search engines to analyze clickstream UNLESS….they the site is running Google Analytics.

If a site uses Google Analytics - THEN Google does have the traffic information and could actually use it.  The problem is, most sites are not running Google Analytics … so while this is an interesting idea, I don’t think it really pans out.

Via Brickman comes an interesting WMW thread stating Google may be using traffic analysis and user feedback (clickstreams, etc) to help determine the quality of a site.

I have spoke to a well known engineer at another major engine who told me that it plays a significant role in their engine.

SeoRoundtable says that Google uses the number of clicks on the search results as a ranking factor

How does Google measure traffic of a Web site? They can look at dozens of factors, including clicks from the SERPs to your page, and then back. They can use the Google Toolbar data, AdSense data, AdWords data, Analytics (although they would never), and so on. Just keep thinking….

That’s doable.  I know I can pull that kind of data from search engines I’m involved with….but using it as a ranking factor might be more of wishful thinking than an actual practice as those links in the search results that are in the top get clicked on more anyway….so what that just reinforce the lousy ranking system that may be in place?