In his doctoral dissertation, Kai Huotari studied how TV live-tweeting influenced the TV viewing experience. He interviewed 45 live-tweeters and analyzed more than 4,000 TV live-tweets sent in the U.S. in 2011–12. The study identified four distinct groups of users live-tweeting about TV programs (fanatic TV live-tweeters, systematic TV live-tweeters, sporadic TV live-tweeters, and active Twitter users), four main categories of TV live-tweets (courtesy tweets, outlet tweets, selection tweets, and analysis tweets), described several TV live-tweeting practices from preparation practices to reading and writing live-tweets and to the use of Twitter functions, and revealed that a TV live-tweeter is an empowered TV viewer who can, by experientializing live-tweeting into his or her TV viewing, personalize and control his or her TV-viewing experience better than before, express him- or herself more fully, and reach a large enough audience and acceptance for his or her ideas.