On fixed networks in North America, Netflix is the "unchallenged leader" when it comes to traffic, controlling 32.3 percent of downstream traffic during peak periods. Coming in second is YouTube, with 17.1 percent of peak downstream traffic in North America, up from 13.8 percent last year.
Globally, however, YouTube is the leader when it comes to fixed and mobile networks, making the Google-owned video site "the leading source of Internet traffic in the entire world," Sandvine said.
In North America, Netflix's traffic share dropped a fraction of a percent since last year, but "it should not be interpreted as a decline in the popularity of the service at the expense of their competitors," Sandvine concluded. "In fact, competing pay-video services such as Amazon (1.31 percent) and HBO GO (0.34 percent) saw their relative share decline in a greater amount than that of Netflix."
On mobile alone, YouTube is also the top service with 27.3 percent of peak downstream traffic in North America, down from 31 percent. Netflix is nipping at its heels, though.
"While watching a full length movie, or a 22 minute sitcom, on a 4-inch smartphone screen may not be the ideal viewing experience for everyone, for many subscribers it is becoming a viable experience," Sandvine said. "Netflix's downstream traffic share in North America almost doubled from 2.2 percent to 4 percent in just 12 months time, and we believe that that this number will increase going forward and that longer form video as a whole will become more commonplace on mobile networks in North America."
YouTube's efforts to produce longer-form videos and live-streaming events hasn't really helped boost its traffic share, Sandvine said.
"Instead, we believe the increase is attributed to the continued growth of smartphone and tablet use within the home (i.e. 'Home Roaming'); as observed in this study, such devices consume over a quarter of all streaming audio and video on fixed access networks," according to Sandvine.
When it comes to streaming music, meanwhile, Pandora is still the leader, and its share of downstream traffic is actually higher during non-peak times (3.62 percent vs. 3.35 percent) - mostly because people are listening all day while at work.
Netflix, meanwhile, released its ISP rankings for April this week, which provides details on which providers offer the best Netflix streaming experience. In the U.S., Google Fiber was still No. 1, followed by Cablevision, Cox, and Suddenlink.
During the first quarter, Netflix users collectively streamed over 4 billion hours of films and TV shows, Netflix announced last month.
