Nielsen: Smartphones and the Internet are eating our TV time

The use of Internet-ready devices like smartphones appears to have seriously cut into the time Americans spend watching traditional TV, new Nielsen data show, potentially undercutting the notion that mobile devices merely serve as "second screens" while people are plopped in front of the set. Data show an increase in the number of 18-to-34-year-olds who used a smartphone, tablet or TV-connected device like a streaming box or game console. That grew 26 percent in May compared with a year earlier, to an average of 8.5 million people per minute. Those devices, which all showed gains in usage, more than offset declines in TV, radio and computers. In the same age group, the demographic most highly coveted by advertisers, use of those devices fell 8 percent over the same period to a combined 16.6 million people per minute.

It's not a one-to-one tradeoff, however. Sometimes people are using smartphones while watching TV, or using them outside the home where it wouldn't cut into TV time. Some mobile device use is also, well, to watch TV shows. The study counts all apps, Web surfing and game play but not texts or calling. Still, the trends are strong enough to confirm a trend in other Nielsen data that found viewing of traditional TV -- through a cable or satellite connection or an antenna -- peaked in the 2009-10 season.