Apparently Google.com is using a stronger geo targeting filter this week causing some people to gain much more traffic and some people to lose a lot.

In the UK Google.com has a 15% market share compared to the 75% market share that Google.co.uk has so it could be quite a big issue for some UK websites. Personally I’m not seeing much of a change looking from here in the UK but looking on a US proxy there do seem to be less .co.uk sites ranking well.