It's not the only reason but the US has a scale and population density disadvantage which makes it more expensive to roll out technology nationwide. You can see

It's not the only reason but the US has a scale and population density disadvantage which makes it more expensive to roll out technology nationwide. You can see this with cellphones as well - rolling out 3G coverage across the UK is a lot cheaper 'per customer' than it is across the US, so we have better coverage.