The 13.8 million Tweets were seen by 12.8 million people, according to Nielsen SocialGuide, and had 862.4 million impressions. Those Tweets were sent by 2.6 million authors.
Nielsen SocialGuide provides data on the number of Tweets sent and unique Twitter accounts that tweeted about the #Grammys and the live reach of the program (unique audience, impressions). Data is measured three hours before, during and three hours after the airing of the #Grammys, local time — and in the U.S. only.
The ratings from Nielsen show the telecast had 28.5 million viewers, the second-biggest Grammys audience since 1993.
You can view additional data around the show released by Twitter tracking the global conversation during the telecast on the east coast here.