Rankings drop in UK and AU but not US

[theLotter]

After the last Panda update on Jan. 22 my rankings dropped significantly in the AU and UK but not in the US.

We operate in UK and AU and not the US so if anything the rankings should be the opposite (which also obviously would be preferred)

Any ideas for why this would occur?

[TomRayner]

Obviously, can't be completely certain why the drop would have occurred, other than explaining the many ranking factors that you probably already know about.

What I would point out, however, is that each region acts like a different algorithm.  They're all very much based on the same one, but I think there's definitely a case that some ranking factors are more important in other regions.

Give you some examples from what I've seen: On-page optimisation in Google France can make a big difference.  I've seen a number of clients and sites (only correlation, not proof) that have tweaked their on-page and had really significant gains.  Another example is Google NL. All that Penguin stuff that happened last year? Well, for many niches it looks like someone forgot to tell the Dutch because you can see an almighty amount of spam ranking very, very well.

I realise this doesn't help you very much, but the reason I mention it is that, if you have the time and resource, it really does pay to look at the ranking factors and their "weight" for yourself - do your own testing based on best practices, if possible, and you might be able to see some differences between Google UK and AU.