The right click distance can improve your search engine rankings

What is click distance?

Click distance is the number of clicks it takes to get to a web page from the home page of your web site. If you need 5 clicks from your home page to go to page A and 2 clicks from you home page to get to page B then page B has a smaller click distance than page A.

Why is click distance important?

Some search engines (including Google) seem to take click distance into account when calculating the ranking of web pages. The lower the click distance, the more value is given to a web page.
In addition to the click distance, some search engines might also take the directory structure into account.
A web page with the URL www.example.com/page.htm is considered more important than a page with a URL that points to a sub directory: www.example.com/here/there/whereever/page.htm

How can you influence the click distance on your web site?

It's likely that a clean site with less click distance gets better Google rankings than a site with a cluttered navigation.
An easy way to make every page of your web site available with at most two clicks is putting a sitemap link on every web page. Using Google's Sitemaps service doesn't help because it does not change the click distance of your web site. You have to put a normal sitemap on your web site.
If you use a normal sitemap on your web site then you don't have to participate in Google's Sitemaps program because Google will find all of your pages through your regular sitemap.

Are there official documents about click distance?

A MSN Search patent application with the title System and method for ranking search results using click distance contains further information about click distance and its possible effects on web page rankings.