There are numbers of defintions about Popular culture. Dictionary.com defines as follow:
Pop Culture(popular culture) is cultural activities or commercial products reflecting, suited to, or aimed at the tastes of the general masses of people.Considering above, my perspective of pop culture is basically every activities or products that relates to people's daily life, especially angle of the amusement. For example, television program, music, clothes, magazines, book, internets, movies, sports, and etc.
Social media usage in pop culture
http://www.reelempire.com/ Social media that for people who want to share their movie recommendation.
http://www.weeworld.com/ People can comunnicate with using avater i this SNS.