Robert_Charlton - 8:20 pm on Feb 26, 2009 (gmt 0)

It's easier to see clear co-occurrence with a multiple tilde search. On searches cited above, eg, try this search for...

~apple ~laptop [google.com].

Note that Dell laptops is highlighted as the #3 result.

Another tilde search for me that illustrates a significant degree of co-occurrence correlation is this one...

~ford ~taurus [google.com].

Note the highlighted results showing for Honda Accord. (I know that this particular search result has been around for a while).

Aaron's article is an impressive bit of research, and checking the RankPulse charts makes it clear that something changed in mid-January.

I don't think that co-occurrence between a brandname and keyword, by itself, explains the ranking jump in the searches I've had a chance to examine. There still need to be other factors for a page to rank.

While these two examples, eg, that Aaron cited are not what you'd call conventially well optimized, there are clues provided to Google for the pages that rank...

- Hallmark ranking for gifts - Radioshack ranking for electronics

In the case of Hallmark, "gifts" does occur in the title and you see it twice in the text cache. In the case of Radio Shack, "electronics" is present in inbound links to the page and is roughly the ninth word in the home page's rather long title.

I haven't had a chance to check enough brands to see whether any rank without apparent onsite or link-driven reasons for ranking. My instinct says that it's unlikely, and that we're seeing the co-occurrence knob being turned up, but operating together with traditional algo factors.

One of the questions I'd ask in relation to this discussion is whether this is a boost applied just to brands, or whether it's an overall co-occurence boost of some kind, perhaps one that only kicks in when there's a strong link profile for the co-occurring term (as there would be on a branded page).

[edited by: Robert_Charlton at 8:27 pm (utc) on Feb. 26, 2009]