Binge-viewing is fast becoming the new national pastime: 70% of U.S. consumers now binge-watch TV shows, with Americans gulping down an average of five episodes per marathon session, according to a study by consulting firm Deloitte.

The study, conducted last fall, also found that 61% of streaming subscribers ranked Internet-video services among their three most-valued paid services, more than tripling in the last three years (from 17% in 2012).

In addition, millennials aged 14-25 value streaming-video subscriptions to services like Netflix and Hulu Plus more than pay TV, while older cohorts still rated cable or satellite television higher. About 46% of Americans now subscribe to streaming video services, and consumers 14-25 now spend more time watching online-video services than live TV, according to the Deloitte study.

The ongoing shift in media consumption among younger consumers continues to threaten traditional business models, while it also presents new opportunities for Hollywood to reach the next generation, said Kevin Westcott, Deloitte principal and U.S. media and entertainment consulting leader.

Millennials are “streaming more than watching TV, they value streaming more than TV, and when they do watch TV they are doing an average of four other things at a time,” he said.

Overall, about 31% of those surveyed said they binge TV shows on a weekly basis, and 36% of those aged 19-25 say they binge weekly. TV dramas remain the most popular genre among bingers: 53% said they most often binge-watch television dramas, followed by comedy at 17% and reality TV at 7%.

In another significant finding, nearly three-fourths of millennials aged 19-32 said their buying decisions are influenced by social-media recommendations — versus 63% who said TV ads affect their purchase plans, according to the Deloitte study. In addition, more than one-third of consumers under 50 and almost half of millennials said their buying decisions are influenced by endorsements from online personalities.

“Television is still very powerful, but for younger generations social has eclipsed TV for buying decisions,” Westcott said. “If I’m a marketer, I have to think about, how do I reach them through social channels… and how to leverage endorsements from social influencers.”

Deloitte’s 10th annual “Digital Democracy Survey” polled 2,205 U.S. consumers online from Nov. 5-19, 2015, with data weighted to reflect a representative view of the American population.