GetGlue, a social network that allows people to check-in, discuss and refer TV programs and movies, now has more than 3 million users and 500 million posts. Representing the crest of a massive wave, GetGlue embodies the spirit of the social TV trend. Social TV integrates online media experiences with traditional broadcast media, making social (and to some extent mobile) a core feature of the fully transmedia experience. Marketers can capitalize on this very real opportunity. According to Nielsen, 68% of people view TV while using their tablets several times a week or more. Another 64% do the same with their smartphones. Geoff Livingston on Google+