limoshawn - 12:28 pm on Feb 17, 2008 (gmt 0)

All bias conspiracy theory aside, it seems that the main factor would be incoming links to inside pages. I would have thought that on page navigational link structure or user behavior would have played a bigger factor in sitelinks but maybe not. My reason for this thinking is "/forum89/". There doesn’t appear to be any navigational links from the home page to this forum so that would seem to rule out nav links and user behavior.

So while a directory like "foo" may be very popular, as Tedster said it is very off target and probably doesn’t get near as many incoming links and an AdWords or AdSense forum.

Another thought as I sit here is bookmarking. I wonder if the amount of times a page from a site has been saved to favorites might play a role.