The BBC covers an interesting report on what made broadband work in South Korea (which has 60% household penetration – the highest in the world). It was strongly backed by government and sold to the public as an educational and entertainment tool. Also, there are several competing sources of broadband and helpfully, “80% of the population live in urban areas and nearly half of those live in large apartment blocks with a single communication room for broadband connections.”
Also see a more lengthy article in Wired which concentrates more on the social side…
I do wish there were more articles around about this – though I suspect that many of the things that made broadband work in Korea would be hard to reproduce elsewhere, like the more group-oriented culture and the dense population.