The data in Nielsen‘s latest quarterly Cross-Platform Report, out today, provides a little texture to the debate over whether the pay TV ecosystem will soon begin to crumble as consumers either cut the cord, or young people don’t subscribe when they set out on their own. The ratings agency says it’s going to start including data in its measured samples from homes where people watch lots of video, but not in a way that fits the traditional definition of a TV household — one where people watch broadcast or pay TV programming on a TV set. Turns out there are more than 5M so-called “zero TV” homes now, up from from more than 2M in 2007. Nielsen’s term for the group is a little deceptive: 75% have at least one TV set. But 37% watch video content on computers, 8% on smartphones, and 6% on tablets. A little less than half (48%) watch TV content through subscription services, which Nielsen doesn’t identify but I’d assume includes a lot of Netflix customers. As you might imagine, people in these “zero TV” homes tend to be a lot younger than others in traditional TV households, and 41.2% live alone (vs. 26.2% of people in TV households). Some 36% of “zero TV” people say that cost is the main reason why they opt out of the traditional system, while 31% say that they simply lack interest. But 18% say that they’d consider subscribing to pay TV.

The Nielsen report shows that the number of pay TV households (cable, telco, and satellite) dropped 1.1% to 102.3M in the year that ended in Q4 while broadcast-only homes increased 2.1% to 11.3M. Meanwhile homes with a DVR increased 8% to 50.7M while those with a DVD or Blu-ray player fell 2.8% to 95.2M. The average time each person spent watching TV per day was up slightly to 5:28 hours, with 4:39 on live TV (vs 4:35 at the end of 2011), 25 minutes on DVR playback (vs. 22 minutes), 13 minutes from video games (no change), and 11 minutes from discs (no change).