Pardon for placing them under the pop-culture category. Let's put them in a fourth category named "technology". Indeed they are a melting-pot of cultures, and during the 1900s it spread to Norway. Pop-culture spread, and even people in Europe thought America was the greatest country in the world. They wanted American <everything>. And eating typical American food, like hamburgers, meant cool. Although it was originally a German food.

Both Apple and Windows are American companies. Most of the games we play are American. Most of the Internet we visit is American or also have American users.

I am not giving America credit for these things, but America as "the first super power in the world on the technological forefront", they developed and spread these things to us. And we picked up what had become American culture (the parts we saw).