The Council for Research Excellence/Keller Fay Group found that millennials were the age group most likely to engage with social media while watching TV.
Social networking is used by more than six in 10 web users via PC, mobile and tablet.
73% of respondents used branded pages on social networks to deliver messages, making it the most popular social media tactic among social advertisers.
Fully 61% of new vehicle buyers in so-called mature markets, including the US, said they had used some form of social channel.
Online video sharing was a top internet activity among US web users, according to a December 2012 study from NetBase, especially among younger consumers.
Users exposed to a Promoted Tweet impression had an average 22% higher message association than those not exposed to Promoted Tweets.
The percentage of internet users who are on Twitter has doubled since November 2010, currently standing at 16%.
These Primary Mobile Users are 57% more likely to compose original tweets, 63% more likely to click on links.
This heatmap illustrates the order in which people focus their attention on Twitter pages.