[repsilat]

Finland has a higher proportion of urban residents than the US. The US is also known for its huge number of small and mid-sized cities and population spread all over the country, whereas (proportionately) more of Finland is essentially empty.

[distances]

That may be true but doesn't really factor in to the discussion of coverage and competition: even if essentially empty, Finland is still covered. Coverage maps for the two biggest operators:

* Sonera: http://www.sonera.fi/asiakastuki/verkkokartat/kuuluvuuskartt...

* Elisa: http://elisa.fi/kuuluvuus

Notice how 4G already covers almost half of Finland, and 3G basically everything excluding larger swaths of forest.