That number is double the number in 2008, not surprising considering the growth of YouTube, Hulu, Netflix, and Amazon content in that time.
The LA Times points out that this doesn’t mean that most people are watching that amount of video:
The one wrinkle: Nielsen found that the total number of online viewers in the U.S. -- about 150 million as of August -- was growing at half the speed of the amount of video being watched. Meaning people who are watching online video are watching a lot more than they used to -- but there are still plenty of people who aren't watching it at all: about half of the U.S. population.
I think that’s kind of curious. It’s easy for the tech savvy among us to think that everyone’s on Netflix or similar services because it’s so dang easy. But a lot of the country does not find it easy, either because the process is too complicated, the devices to watch these things are unattainable, or the broadband connections are just too lousy.
I think a lot of people and companies are looking to a video future that’s way more broadband than coaxial cable or satellite dish but it’s not here yet.