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I think (!) Google base these regional results on some kind of local PageRank. In my experience a site that only has links from sites hosted within one country will have much better SERP positions for that country's local Google site.
For a site published in Finnish, hosted in Finland and heavily linked from other Finnish sites this would be great. At least if the target audience are Finns using google.fi. This site will rank better in SERPs even for words used in other languages.
However, for a site targeting Americans, published in English, hosted in Finland, struggeling for links but mainly linked from other Finnish sites it, as you say, bad. What good is it to rank good on Google.fi when your visitors search from other Google sites?
The same difference clearly exists for UK sites.
My advice is. Get links from sites situated in the country where your potential customers are, and if you target a small language. Host your site locally and don't even bother looking for links from other countries.