During Sunday's Super Bowl, more than 5.4 million people made a total of 12.2 million tweets or other social-media comments about the game—plus nearly another million comments on the advertisements—in the largest-ever such TV-triggered outpouring in the history of social media.

The comment numbers, clocking in at six times more than for last year's big game, were another sign of social media's disproportionate attention to television content, a phenomenon broadcasters and advertisers are increasingly trying to harness. Most of the comments were made on Twitter, which saw total overall activity double—but not rise sixfold—in 2011.

Reflecting this outburst, GetGlue, a social-networking site that allows TV watchers to "check in" to note they are watching a show—and then share opinions and recommendations—enjoyed more than 150,000 check-ins during game night, an all-time high for the startup—and a sharp rise from 20,000 check-ins last year.

The surging discussion of television content on social media is being actively cultivated by social-networking sites, and harnessed by TV and ad executives as way to promote shows and products, and as a real-time barometer of what viewers like and dislike.