Receptional_Andy - 12:02 pm on Jun 21, 2008 (gmt 0)

A scenario I see fairly commonly: many sites have .com and .co.uk versions - often pretty much a duplicate. While the .com will usually outperform the .co.uk in any general-purpose search (the regional site is buried in results as a result of similarity/duplication), the local site will normally be returned for brand-based searches.

An easy specific: Google.co.uk is the first result for 'Google' in Google.co.uk.

Now, this could be as a result of clickthrough data, however I don't think it's that simple. Google.com results do not list google.co.uk in the top 10 at all, and so where would the clicks come from?

I think a factor may be the 'regionality' of a search - i.e. how likely it is that the visitor is looking for a region-specific resource.