TV viewers continue to increase their usage of social media when it comes to TV programs. A new survey says two in five online U.S. adults -- 43% -- have gone to the Web to comment, post, or read something about a TV show. The findings are from Harris Interactive and 24/7 Wall St., a financial news and opinion site focused on the U.S. and global equity markets. Among 80 million+ people, one-third -- 33% -- have done so after watching a TV show or program. Somewhat less -- 18% -- have done so before watching a TV show, and 17% are interacting with social media while watching a TV show or program. Younger online adults 18-34 are the big users of social media here -- 59% have said they have engaged with TV shows this way. The numbers are 40% for older 35- to-44-year-olds; 36% for 45- to-54-year-old viewers/users; and 28% for those who are 55 and older. In looking at key behavior while watching TV, 31% of 18-34 adults say they are interacting while viewing. At the older end of the age spectrum, only 5% who are 55 and older do this activity. Where does this social media activity happen? Fifty-three percent post comments on their own or to a friend's Facebook page, or a Twitter account or a blog. Forty-four percent do so on a Web site or page created by the TV content provider, such as a TV network's Facebook page or site. About one-third do so on related TV/media entertainment or news sites. Women are more likely than men to engage in an individual forum -- 57% to 50% -- while men are more likely than women to do so on a separate media outlet's site: 38% to 27%. Why do people use social media in regard to a TV show? Three-quarters of adults do it to gain more program information, while two-thirds do it for the analysis or summary or as an additional source of entertainment. About half say it's important to engage with other viewers.