That's bad news for cable and satellite TV providers. Americans are increasingly watching TV shows and movies on Netflix (NFLX), Hulu, Amazon.com (AMZN) streaming and other services. CBS (CBS) and HBO (TWX) have announced standalone streaming services as well.
About 45 percent of Americans stream television shows at least once a month, according to research firm eMarketer. That number is expected to increase to 53 percent or 175 million people by 2018, it says.
According to the Nielsen report, which came out Wednesday, the average daily time spent watching live TV fell 12 minutes in the third quarter to four hours and 32 minutes. That means it dropped nearly 4 percent to 141 hours a month.
Meanwhile, time spent watching streaming services jumped 60 percent to nearly 11 hours each month.
That's still a small amount compared with live TV, but it is growing quickly.
"Content is still king, but consumers are shaping their own content-discovery experience, and the evolving media landscape has not lessened consumer demand for quality, professionally produced content," Dounia Turrill, senior vice president of insights at Nielsen, said in a statement. "What has changed is the number and reliability of new media available to viewers."