Subscribers watch about an hour of Netflix a day

So Netflix (s NFLX) announced Wednesday morning that members watched more than 2 billion hours of video on its streaming video service in the fourth quarter of 2011. Let’s do some back-of-the-envelope math and figure out what that really means.
Dividing 2 billion hours by the roughly 24 million subscribers that Netflix has tells you that on average, each watched about 83 hours of video during the quarter. Divide that by the 92 days between October and December, and you find the average account streamed about 54 minutes of Netflix video each day. While that’s still just 20 percent of the five hours the average viewer spends watching traditional TV, according to Nielsen, (s nlsn) it tells you a little something about where the industry might be headed.
Until now, services like Netflix have mostly been seen as complementary to what people watch through their cable subscriptions each night. But let’s face it: There aren’t that many hours in the day, and when one considers work, dinner, family time and then five hours of TV and another hour of Netflix (not to mention sleep!), it becomes pretty clear that sooner or later that Netflix time is going to start eating into usual TV time — that is, if it hasn’t already.