I always heard that search results on google aren’t influenced by which portal you use. A quick verification at www.google.ca and www.google.de for instance shows this to be true… Most of the time! However, I just googled for “ebay” and the german google listed ebay.de as the first hit, followed by the austrian ebay, whereas the canadian google lists ebay.com, ebay.co.uk and then ebay.de as the third option.
Interesting stuff 