Google Toolbar Affects Related Sites?
Google Use Data From Google Toolbar To Rank Related Websites?
An interesting observation about the Google toolbar and the [related:] command theorizes that the GOOG toolbar influences the perceived relationship between sites.
In working on a client's site I frequently needed a second site -- that was totally irrelevant in terms of theme, but, relevant to to the work I was doing -- for reference, and would often switch between these two sites.
Several weeks later, I noticed the irrelevant site listed in a Google search for related:www.client-site.com (note though, that the reverse was not true). Given the total irrelevance of these two sites I can only conclude that Google uses data from Google Toolbar users' visiting habits as part of their algorithm for deciding related sites -- actually I was using a Firefox PageRank extension, but since this sends the same data about URLs you visit back to Google, it's incidental.
There's some obvious information missing on the post. For example, were the sites linked? What firefox extension? etc but as nullbit is a member here im sure those questions can be answered...

related sites - hmmmm
Related sites are almost as good as Google Synonyms if you want a laugh one day.
I've noticed that a lot of the SG mods and regulars appear in each others 'related sites' searches - despite our sites being pretty diverse and despite SG not appearing in many of the lists.
I always assumed it was to do with common linkage from SG to the sites - there's no other common factor really. GHN related sites have been very quirky and quite flatteringly include the BBC, the GoogleBlog and SEW, so again I assumed it was common linkage, but perhaps it is people with toolbars who visit the same sites regularily.
That only one person can effect it though would be concerning....
Re: What site
I didn't post the clients site because the other site no longer shows up in a related: search, so it would't prove anything anyway.
The firefox extension is this one. Which sends the same PageRank requests back to Google to as the toolbar does.
Re: were the sites linked?
Not as far I could tell.
I also checked thoroughly for any crawlable log/referrer link pages, and didn't find any.
Google's long tenticles
Why wouldn't they give a certain weight to their users' habit? I personaly think they should. On another side, I totally agree with Gurtie
Take Amazon's Alexa toolbar for example. I know from one of my sites that when I was pushing users to download it, my alexa ranking sky-rocketed, why? Shouldn't they be analyzing the internet traffic in general and not only habits of users that have the toolbar?
Admit it makes you want to distribute that toolbar to all your users, nice incentive they give you:
good referrer job = better ranking
Am not an expert in PR, so I'll ask the right people to tell me: how does G Toolbar user's habit effect on PR?
Another interesting thing to learn (or to get working on): what if I surf around the site or just close the window (press back button), would that tell Google's intelligent machines the site's relevance to me as a user? And maybe then use that information in the algorithm for future search results by other people?
toolbar & co citation
a while ago webmaster-forum.net (or something like that, the old name for V7N) was associated with some porn sites because the old owners of the domain name had a forum there and had some moderators who ran a bunch of porn sites.
I think a friend also said co citation may also have an effect on the related sites command.
this is all bollocks
The related command finds sites which appear on the same page of certain backlinks.
related not useful
Yeah, I've never seen a useful result in 'related' results.
For my sites they commonly show those of my sites that reside on the same hosting - I assume they are tracking the IP, as I only use a few hosts - and some of the backlinks
I've seen the same...
...SlyOldDog has.
I don't mean the bollocks part ;-] I mean I've seen that links from page A to page B and to page C, can cause B and C to be related. It happens a lot with forum sig links.
The related command finds
I don't believe anybody suggested that was not the case. Just that it maybe that the toolbar adds to this.
Anyone that's spent more than 2mins browsing an seo resource knows that backlinks affect what Google sees as your related sites.
That's not the point.
Sorry Nick
Sorry Nick
I didn't see anything on the site you posted about how related is supposed to work. It looks like he doesn't know.
Pure speculation.
Leadegroot - IP is nothing to do with it IMHO.
I see related sites
I see related sites apparently drawn from the same DMOZ cat i.e. actually drawn from the ODP/Google dir rather than happening to coincide with DMOZ listings.