Nielsen is now measuring the “unique audience” for Twitter posts related to television, providing advertising and television executives with a more complete view of social TV. The company introduced Nielsen Twitter TV Ratings yesterday, a previously announced service that intends to measure the reach of Twitter conversations related to television shows. Nielsen expects that networks will eventually promote Twitter TV Ratings the same way they promote traditional broadcast ratings.

“Only 98,600 people wrote messages on Twitter about the two-hour season premiere of ‘Grey’s Anatomy’ last month. That’s a tiny fraction of the 9.3 million who, according to Nielsen, watched the show that night,” reports The New York Times. “But the posts, 225,000 of them in total, were seen by millions of Twitter users, some of whom might have fired up their digital video recorders or laptops to watch the episode later.”

Measures of posts about specific TV shows are just the beginning, as Nielsen looks to measure the number of tweets in addition to their full scope. According to Nielsen’s algorithms, for example, the 225,000 posts about “Grey’s Anatomy” were seen by 2.8 million Twitter accounts.

“It is impossible to say how many of those users watched the show as a result of the posts, but previous research has found that Twitter activity sometimes spurs viewership,” notes NYT. “Twitter has made collaboration with the television industry a priority as it seeks to impress investors; the prospectus for its initial public offering, published Thursday, mentioned television 42 times.”

The Nielsen data “highlights that the programs that generate the most Twitter activity often aren’t the ones with the highest viewership,” reports The Wall Street Journal. Despite the difference, advertisers acknowledge the potential value in knowing which shows create interest on Twitter, and to many this is a factor when buying TV ad time. The idea is that if viewers are engaged on Twitter regarding a show, then ads are also seen, according to Steve Kalb, director of video investment at advertising firm Mullen.

While Nielsen hopes that its new ratings will be used by TV networks to promote performance, it is not clear how many networks or advertisers are currently paying to receive overnight data.

“This is just the beginning; the data hasn’t been available until now,” said Sean Casey, senior VP and founder of analytics firm SocialGuide, which Nielsen purchased last year to create its new product.

“Some networks may question Nielsen’s methodology, especially since a TV-related post is said to be viewed whenever it is loaded on the Web or whenever it shows up on screen, however briefly, on a mobile device,” suggests NYT. “More generally, skepticism abounds about how representative Twitter chatter is — or isn’t.”

“What people often lose sight of is the fact that the overwhelming majority of conversations about TV shows still take place offline,” said Ed Keller, chief exec of market research firm the Keller Fay Group.

Related Stories:
Facebook Shares Social User Data with Major TV Networks, ETCentric, 10/1/13
Advertising Week: Twitter Sees Opportunities in Social TV, ETCentric, 9/26/13
Social TV: Twitter Launching Paid Ad Products for Networks, ETCentric, 9/24/13
Nielsen to Include Tablets and Phones in TV Viewership Data, ETCentric, 9/23/13