(USA Today) -- All that tweeting that you do while watching your favorite TV shows is having an effect.
New research from Nielsen suggests that fans tweeting about programs during live broadcasts can lead to increased viewership. That may seem an obvious finding, but until now the TV measurement firm had only established that there is some link between social media and TV viewing.
This new research is the first to show that Twitter activity can influence TV ratings. "That's what we speculate is going on," says Mike Hess, Nielsen's executive vice president of media analytics, "that the tweeters are watching the program and then by sending the tweets out, other people start tuning in as well."
Nielsen compared - minute-by-minute - the tweets and TV ratings for 211 prime-time TV broadcasts including sports and award shows and 10 episodes each of 20 specific TV series during fall 2012 and spring 2013.
For nearly one-third (29%) of the episodes, Nielsen found that related tweets caused significant changes in the TV rating. And in about half (48%) of the TV episodes, changes in the minute-by-minute TV ratings led to a change in tweets, too. So, for instance, as more viewers tuned in, it was likely that more tweets about the program were fired off.
Nielsen did not release data on Twitter effects on ratings for specific shows, but did reveal that for genres such as competitive reality TV, the tweets had a higher effect. With dramas there was a lower effect, Hess says.
"There's more work to do to find out what those exact relationships are," Hess says. "And so further research can be used now to determine the actual nature of those relationships, in other words, how many tweets does it take to cause an increase, how big is the increase and so on."
More than half of those who own tablets (53%) and smartphones(52%) engage in social media while watching TV, Nielsen found in separate research. And at least one-fifth - 21% of tablet owners and 18% of smartphone owners - spent time reading social-media discussions about the program they were viewing. And 15% of tablet users, along with 10% of smartphone users, watched a program because of something read on social-media sites.
Other earlier Nielsen research on Twitter and TV ratings found a correlation between Twitter activity and TV ratings. And in the works for the fall TV season is a new Nielsen Twitter TV rating that measures TV audiences' social activity.
"We are saying that there is a 'there' there," Hess says. "We know that big companies, broadcasters and other advertisers all have their social groups within those companies and some of what they are doing is clearly working."
At Twitter, the social-media company assumed that, "so it's really exciting to see an organization as respected as Nielsen dive in and take a closer look," says spokeswoman Rachael Horwitz.
"When the program is on the air, you no longer have to watch that show with just the people in your own living room," she says. "You can share that experience with other fans of the show and folks you may not know, which includes the talent and the stars and writers of the show and athletes that you like (because) famous folks chime in as well. So the whole thing becomes really, really fun."