SAN DIEGO — Nielsen has begun engaging movie studios and TV networks on a new metric — tweets per impression — that gauges the social impact of entertainment marketing efforts.

Erika Faust, VP of client services at Nielsen Social, teased “TPI” Wednesday at the Media Insights and Engagement conference. “We’re going to spend a lot more time focusing on this category,” she said, noting the metric is still early in development. “Advertisers now want to start looking at this.”

TPI maps the number of impressions a commercial has on TV against the number of tweets referencing that particular impression minutes after the commercial airs. In addition, TPI can be cross-indexed with marketing spend to measure bang for the buck.

While TPI isn’t limited to the entertainment industry, Faust said there’s been significant interest from studios, which can adjust their TV advertising plans in real time based on input from the metric, and networks, which can refine promotional strategies for  own programming on air.

Faust declined to specify which networks or studios are using TPI but offered anonymized data citing actual instances.

“It’s early days but we’re finding a lot of interest from studios using social as another indicator and for networks to use to their advantage as well.”

Faust revealed TPI in a broader presentation that touched on Twitter trends during live linear programming, delayed viewing seven days after premiere and “buzz” in advance of series premieres.

She disclosed that 18 million people sent a tweet about a TV show in the last six months, totaling 433 million tweets. In addition, 20 million people sent tweets about brands, totaling 335 million tweets. Faust emphasized a heavy overlap between the two groups as a sweet spot for marketers to target.

Nielsen Social was previously known as SocialGuide, which Nielsen acquired in 2012.