What Did Google Change Last Month?

What are the reasons for the big changes in the google results?

[Mr_Who]

Hello guys,

I know there was one topic about major google changes but in this topic most of the posts were about what is going on and less about the reasons.
I want to ask now what do you think are the rasons caused the big changes last month?
Is there any major changes or just PR update?

I think there a few think google changed:
1. The importance of the PR is decreased. I see a lot of sites with with less PR on the top positions. I even saw a .txt file ranked in top 10 for a competitive word.
2. On the other hand the sites with less keyword density are ranked well that leads me to a conclusion that there is may be some 3th very impotrtant factor determinig the results.
3. What is this factor? Is it the freshness of the content? I still can't find it.

What do you think?

[pardo]

We had some serious drop in traffic since 17/18 december. Now things slowly seems to come back.

I noticed our .com traffic has dropped many many times but co.uk traffic seems to stay the same.

Also noticed that traffic on commercial keywords and with affiliate urls have been hurt.

From SE's perspective could be logic to devalue affiliate links, on the other hand it depends on the way the site is coping with affiliate products.

Kelkoo and the other shopping search engines exist from affiliate marketing haven't had time to see if they have been hit also...

[GranPops]

I mentioned earlier in this thread that, "5 small niche sites that have been No.1 since even before Florida, without links.
Traffic approx. 1000 per week.
Last week disappeared completely."

Still no links but now they are all back again at No.1

[pardo]

...co.uk traffic seems to stay the same...

exploded traffic on co.uk referrals since yesterday

I suspect more 'local'-related adjustments in the algo...

[lammert]

I have seen local adjustments on some of my keywords, i.e. they fall down when searching on Google in different countries with a different language than my pages. But this is not the case for my main keyword. Google for English speaking countries still present the Dutch page as first page for this keyword, although an alternative in English is available. And the English page has higher PR than the Dutch one. Strange. Maybe Google is in the middle of a new PR calculation.

Apart from this I haven't seen any major SERP changes in the keyword range I am looking at. Maybe some areas are affected more than others.