Netflix, already the biggest single driver of Internet bandwidth, boosted its share of peak broadband traffic on North American broadband networks in March 2014, according to a new report.

The No. 1 subscription VOD service accounted for 34.2% of all downstream usage during primetime hours, up from 31.6% in the second half of 2013, according to network-equipment vendor Sandvine. Peak period is defined as 7 p.m. to 11 p.m. on Sandvine’s reports.

YouTube dropped to 13.2% of total peak downstream usage in March from 18.6% in the second half of 2013, according to the report. Amazon Instant Video continues to gain, but still accounts for only 1.9% of downstream traffic vs. 1.6% last fall, while Hulu usage increased slightly from 1.4% to 1.7% share.

Meanwhile, videogame-streaming service Twitch has come on like gangbusters, breaking into the top 15 applications as measured by Sandvine.

Twitch, which claims more than 45 million monthly users, represented 1.35% of all downstream bandwidth on North American fixed-access broadband networks in March 2014, compared with 0.46% last fall. That makes Twitch bigger in terms of usage than HBO Go, which represented 1.24% of downstream traffic in the first-half 2014 report. The services are very different: Twitch’s free live gameplay videos can be streamed from Microsoft Xbox and PlayStation 4 consoles, while HBO Go requires a subscription to the premium channel.

The Sandvine report also examined consumption patterns among different cohorts of users. The top 15% of bandwidth users dominate network usage in North America, accounting for 54% of total monthly network traffic in March. That group consumes on average 212 gigabytes per month, the equivalent of 100 hours of video and more than seven times the 29 GB of a typical subscriber. (Sandvine termed this top 15th percentile of users “cord-cutters,” speculating that they are relying on the Internet for video entertainment — but it doesn’t actually know whether those consumers have canceled pay TV.)

Overall, mean average usage per subscriber for wireline broadband in North America was 51.4 GB in the first half of 2014, up from 44.5 GB last fall. That increase is in line with the 30%-40% annual growth rate in bandwidth consumption ISPs are forecasting for 2014, according to Sandvine.

On North American mobile networks, YouTube led with 17.6% of peak-period downstream bandwidth, followed by Facebook with 14.0%.

Sandvine’s “Global Internet Phenomena Report 1H2014” report is based on a subset of anonymized data from its 250-plus Internet service provider customers worldwide.