Netflix accounts for nearly 35% of US peak time internet traffic

"Netflix continues to dominate North American networks, accounting for 34.9 per cent of downstream traffic in the peak evening hours
Amazon Instant Video has established itself as the second largest paid streaming video service in North America. While still only accounting for 2.6 per cent of downstream traffic, its share has more than doubled in the past 18 months
In advance of plans to start offering a stand-alone streaming subscriptions in the US, HBOGO accounts for just 1 per cent of downstream traffic in the region
On a fixed network in Australasia, where Netflix isn’t even available yet, approximately 2.5 per cent of subscribers are accessing the service and it comprises as much as 4 per cent of peak downstream traffic"

Source:  Data from Sandvine, reported by Advanced Television, 20th November 2014

Full report here