[rayiner]

Half the population of South Korea lives in the Seoul metro area, which has the same population density as the city of San Francisco. The whole of Hong Kong is a single city, again about as dense as San Francisco. The whole country of Japan is about as dense as the state of Massachusetts, the 2nd densest U.S. state. It's about twice as dense as New York, the 7th densest U.S. state.

Dense U.S. states outperform the overall U.S. average significantly (and comparably to Japan): http://www.bizjournals.com/boston/blog/techflash/2014/04/rep....

Out of the 10 U.S. states with the fastest internet, 8 are just the densest states (+D.C.) in a different order.

[adamnemecek]

The thing is that the internet speeds even in the dense areas are disproportionately slower.

[rayiner]

How do you get that? Massachusetts's average is 13.5 Mbps. Japan is 12.8. New Jersey, Maryland, and Delaware are 12 and up, above Switzerland, Sweden, Czech Republic, etc. The dense U.S. states compare very favorably to the top-5.

South Korea is the outlier because half the country lives in a single megacity with the density of San Francisco. The U.S. can't compete with that geographic advantage.