An analysis by NM Incite, a Nielsen/McKinsey Company, found a 9% overall lift in social media "volume" a month before a TV show's start can improve numbers 1% for 18-34 viewers, who are typically the busiest on social media site.
As midseason approaches however the effects of social media on ratings are less. To get the same 1% lift, research says there needs to be a 14% gain in social media buzz. The same is true when it comes to a series finale: A 1% rise in 18-34 viewers needs to have a 14% increase in social media activity.
Looking at specific viewer groups, 18-34 year-old female viewers push social media activity better for reality programs, comedies and dramas. Young male viewers are big with specific competition reality shows and dramas.
Overall, the better social media connection with ratings come with viewer groups 12-17 and 18-34, with young women having a slightly better effect that young men. Men over 50 showed the weakest buzz-to-ratings connection.
The research looked 250 television programs and over 150 million social media sites. Social media metrics for the study included "buzz volume" -- the number of messages about a TV show, messages per individual, and the number of individuals. Also, advertising money to promote the show and prior ratings were factored in.