The LA Times has an interesting (albeit short) article about the television habits of tablet and smartphone users. According to Nielsen, 88% of them tap their devices during TV time at least once a month, 45% supplement the TV screen daily, and 25% do it several times a day.
There is also a specific shout out to Fringe:
Some shows invite smart-screen surfing to supplement their content. "Fringe" fans, for instance, know to check FringePedia while watching the show to decipher the code in the glyphs in the pre-commercial slate or figure out when they missed an Observer appearance in that episode.Hopefully everyone here participates in the weekly Twitter and GetGlue campaigns organized by Fringenuity.
Don't forget you can find all the glyph codes and observer appearances here as well!