tedster - 9:18 pm on Jan 11, 2007 (gmt 0)

Here's an observation that prompts me to do some educated guessing. One of my clients has held the #1 spot for a given search over many years. For the same time period, the #2 spot was held by another domain -- the SERP was really locked down.

Last week the #2 fell to #4 - and none of the top 4 sites show changes (on Yahoo or MSN) to the number of backlinks. The top 4 have also made no content changes to these URLs in many months. So I begin to suspect that Google is shifting the way it weights backlinks altogether. Then, yesterday, Matt Cutts made this comment on his blog:

If you used to have pages in our main web index and now they're in the supplemental results, a good hypothesis is that we might not be counting links to your pages with the same weight as we have in the past. [mattcutts.com...]

How might the weight of backlinks be changing? Obviously we can't know for sure, but one way in which I've been hoping to see this change is to get a little more semantic intelligence into the anchor text analysis. For quite a while it seemed to me that anchor text and page "themes" were running on mere text matches: a link from a page on "fountain pens" could boost a page about "drinking fountains" and so on -- I just made up that example but it is similar to the kind of loosey-goosey thing I've been noticing. So there's one idea.

Another idea would be that forum and blog links now are weighted differently. The previous #2 site is flooded with links from both forums and blogs - legitimate by the way, not placed by automated spam bots - but still a very heavy number.

I have no firm conclusion here, but I thought what I saw was suggestive and wanted to share it.

[edited by: tedster at 10:16 pm (utc) on Jan. 11, 2007]