On a typical week night Netflix accounts for almost a third of all US household internet traffic

"On a normal weeknight, Netflix accounts for almost a third of all Internet traffic entering North American homes. That’s more than YouTube, Hulu, Amazon.com, HBO Go, iTunes, and BitTorrent combined. Traffic to Netflix usually peaks at around 10 p.m. in each time zone, at which point a chart of Internet consumption looks like a python that swallowed a cow. By midnight Pacific time, streaming volume falls off dramatically."
Source:  Business Week, 9th May 2013