If I remember correctly, the telephone system was not part of the postal system in Sweden. They also were an early adopter of the telephone (by world standards) and had a similar penetration/density of subscribers to the US by the 1920's iirc - I've seen the figures, but it was a long time ago and can't remember where. I know that Sweden is generally the test market in Europe for electronics (such as stereo systems, phones, etc).