I found this document:

http://www.census.gov/content/dam/Census/library/publication...

Refer to page 3, where it is reported that 74.5% of households 25 years and up had some internet subscription (and 73.5% had high-speed access). That's no small number, but you could easily call "3 in 4" short of ubiquitous. Note that many of the remaining households have some form of access to the internet, just not a subscription at home.

Wikipedia puts the fraction of the U.S. population using the internet at about 81%.[1] They link to a source, but beware it links straight to an excel file[2].

[1] http://en.wikipedia.org/wiki/Internet_in_the_United_States#A...

[2] http://www.itu.int/en/ITU-D/Statistics/Documents/statistics/...

You would be surprised (maybe?) at the number of rural areas in the U.S. that do not have any real type of access. My parents, for example, are limited to ~1mbit downloads on good days. They cannot stream Netflix and really can't stream Youtube videos either. That 1mbit is with random bursts of noise/packet loss as well. It's pretty crappy. I tried to game there once and saw my latency fluctuate between 200ms and 10,000ms.

I read that as a typo. ("which still isn't as ubiquitous as it is in the U.S." ?)